Joseph Leidy (1823-1891)Photograph by M. P. SimonsProfessor of anatomy (1853-1891) anddirector of the department of biology(1884-1891). Studied medicine at theUniversity of Pennsylvania (M.D.1844). Pioneer of vertebrate paleontologyin America, he corresponded with Darwinwhose Origin of Species was cor­roborated by Leidy's own research whichranged over a wide variety of subjectsand resulted in over 600 publications.Identified the parasite Trichina spiralisin pork. Received the Lyell medal of theGeologicalSociety of London (1884) andthe Cllvier medal of the Institute deFrance (1888).

8

Joseph Leidy

Whenever a body of specialists is established, it seems inevitable for someworthy people to be unaccountably excluded. Although Bache endeavorednot to become embroiled in personal rivalries, he found himself on thedefensive and confessed: "I have been obliged to admit-that there aresome men too mean to bring into our Academy.'" The reverse problemseems to have occurred in the form of opposition in some quarters to theelection of Robert Empie Rogers, professor of chemistry and dean of themedical faculty, as one of the fifty founding members of the NationalAcademy of Sciences. He was one of four brothers associated with theAcademy and the University, another of whom was the founder of theMassachusetts Institute of Technology. Yet another Pennsylvanian,included through no effort of his own, was Joseph Leidy, professor ofanatomy for 38 years in the medical school. Nothing could have been moreforeign to the nature of the man generally regarded as the founder ofAmerican vertebrate paleontology than the political maneuvering of theLazzaroni group. With his dedication to research and the natural world,Leidy was indifferent to reputation and declared himself "too busy totheorize or to make money.'"

On hearing of his pJection to the National Academy of Sciences, hecommented that it was "an illiberal clique, based on Plymouth Rock."Perturbed by the'exclusion of Frederick Hayden, professor of geology atthe University, he consoled his friend and collaborator with theobservation: "I think it will turn out to be a grand humbug, and I intend tohave nothing to do with it.'" Such political concerns lay outside theall-encompassing scientific interests of an investigator who wrote to friendson the question of priority for a geological observation: "I am too littleambitious to give myself any trouble about such a case as that you mention.Even should anyone pass unnoticed more important things I may havedone, I shall feel no regret about the matter.'"

The University of Pennsylvania provided this unassuming scientistwith the setting in which he pursued his studies for almost half a century.His contentment appears in his unwillingness to move when, on the deathof Louis Agassiz, he was offered the Hersey professorship at Harvard.

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Leidy was considered the most prominent naturalist at the time, and aspecial emissary was sent to Philadelphia on this occasion. Leidy gentlypersisted in declining the position and, soon afterwards, accompanied thedisappointed Cambridge courier to the door of his house in Filbert Street.Stepping outside, he scraped a piece of moss from the wall and examinedit closely, reportedly adding: "When I have exhausted al1 the possibilitiesfound here at my own front door I may reconsider my refusal.'"

Joseph Leidy's long association with the University of Pennsylvaniabegan as a student. After receiving his medical degree in 1844, he becamethe assistant of his preceptor, Paul B. Goddard, and also worked in thelaboratory of Robert Hare, the distinguished chemist. A few years later,he served as prosector to the professor of anatomy, William EdmondsHomer. Apart from one brief period as demonstrator of anatomy atFranklin Medical College, Leidy remained at the University of Pennsylvaniafor the rest of his life. As a result of strong support from students andfaculty, he was elected chairman of anatomy on Horner's death in 1853.He was well qualified to succeed the distinguished anatomists Shippen,Wistar, and Physick in one of the two senior chairs of the medical school;at thirty-one, his youthfulness was another point in common with theearlier professors of anatomy.

In one respect, however, Leidy was an exception. After a few years inprivate practice, he abandoned medicine altogether in order to devotehimself entirely to his researches. William Hunt, who was his demonstratorfor ten years, considered it a great tribute to Leidy's personal qualities andhis teaching ability that "for thirty-eight years he filled without objectiona practical chair in an essential1y practical' medical school for science andscience alone.". In 1891, Provost William Pepper declared: "In the deathof Joseph Leidy ... the medical profession in America lost its most lovedand honored member, and American science its most illustriousrepresentative.'" At the time, an amused observer commented that sinceLeidy had not practiced medicine for the past forty-five years "it wasrather like telling an assembly of al1 the tanners of the United States that,in the death of General Grant, they had lost the most beloved member ofthe trade.'"

In later years, Leidy recal1ed that Sir Charles Lyell, author of theinfluential Principles of Geology, had urged him to give up medicine andconcentrate on research. In 1884, Leidy was awarded the Lyel1 Medal bythe Geological Society of London, at which time he commented on theadvice he had received from the award's namesake: "I feel as if Sir Charleshimself was expressing satisfaction in consideration of my having compliedwith his wish, when thirty years ago in my Dwn horne here he said hehoped I would devote my time to palaeontology instead of to medicine."·Leidy was characterized at the time of the award as "careful in observing,accurate in recording, cautious in inferring." An enemy of speculation, he

PIONEERS OF AMERICAN SCIENCE .1

William Wood Gerhard (1809-1872)Photograph by M. P. SimonsMedical alumnus of the University ofPennsylvania and lecturer in the insti­tutes of medicine (physiology) where heintroduced his students to the study ofdisease based on clinical diagnosis andpostmortem examinations (1838-1872)After receiving his MD. (1830), he spenttwo yenrs in Paris nnd collected materialon the pathology of smallpox, pneumoniain children, cholera, and tuberculousmeningitis. His most famous publicationwns on typlJUs, which he distinguishedfor the first time from typhoid fever(1837), and his papers on the diseases ofthe chest (1842) remained classics formany years.

favored scrupulous amalgamation of accurate data over conjectures basedon inadequate evidence. For this reason, he was often called the Cuvier ofAmerica and, appropriately enough, he received the medal commemoratingthe great French zoologist from the Institute de France shortly before hisdeath. 'o

The thoroughness and objectivity so typical of his life's work werealready apparent in his childhood interests. As a boy, Leidy was fascinatedby all aspects of nature and showed an unusual gift for depicting theminutest of observed details. While growing up in Philadelphia, he wouldoften play truant from school where he was bored by study of the classics.He found more to interest him while wandering on the banks of theSchuylkUl and the Wissahickon, collecting specimens of stones, plants, andinsects. At ten his beautiful freehand drawings of shells led his father, aPhiladelphia hatter, to conclude that his second son might consider beinga sign painter when he grew up. Joseph's stepmother, to whom he alwaysrecognized a debt of gratitude, had other ideas on the subject, and theyoung Leidy proceeded to study medicine instead. During his early yearson the medical faculty, Leidy's skill as a draftsman proved advantageousfor both him and the school. In 1851, he and George B. Wood went toEurope where Leidy assembled models and preparations and madedrawings to illustrate Wood's lectures. As the newly elected professor oftheory and practice, Wood was responsible for bringing medicine at theUniversity out of the eighteenth century. From the first, Leidy's ownscientific publications were illustrated by beautiful plates reproduced fromhis detailed drawings.

Joseph Leidy's situation as a scientist with a faculty appointment-aman trained as a physician, but whose financial support came entirely fromhis teaching position-pointed towards future developments in science andacademic medicine. On the other hand, the encyclopedic range of hisscientific interests made him one of the last of that breed of nineteenthcentury naturalists who regarded the whole of nature as their huntingground. Leidy was in the first place a comparative anatomist: his medicalthesis of 1844 was on the comparative anatomy of the eye of vertebratedanimals. The following year, he read a paper on the anatomy of the winkleand one on fossil mollusks before the Boston Society of Natural Historyand the Academy of Natural Sciences of Philadelphia. He was promptlyelected to each at the age of twenty-two. In a textbook, An ElementaryTreatise on Human Anatomy, first published in 1861, the anatomicalnomenclature was simplified for the benefit of students by the substitutionof English terms for the traditional Latin. As usual, the work wasillustrated with Leidy's original drawings of his own dissections.

Although he was neither a mineralogist nor a botanist and publishednothing on these subjects, he nonetheless devoted considerable time tothese aspects of natural history. Every Sunday found him spending a few

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Robert Hare (1781-1858)by John Neagle,finished by I. L. WilliamsProfessor of chemistry (1818-1847). Bornin Philadelphia, he showed interest inchemistry at an early age. Invented theoxyhydrogen blowtorch (1801), as wellas improving the voltaic pile and findinga process for denarcotizing laudanum. Acannon made by him for demonstratingthe explosiveness of hydrogen and oxygencontinued to be used for many years inchemistry classes at the University. Harewrote moral essays under a nom de plumeand, in his last years, became interestedin scientific evidence on spiritualism,publishing his Experimental Investiga­tion of the Spirit Manifestations in 1855.

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hours in the mineral cabinet of the Philadelphia lawyer Richard Vaux, whoclaimed to be the only American to have danced with Queen Victoria. Atthe Centennial Exposition in Philadelphia, Leidy recognized that a minerallabeled as beryl was, in fact, an unusual topaz of considerably greatervalue. He later detected a bogus specimen of quartz in the UniversityMuseum. l1 Throughout his life, specimens of all kinds were sent to himfor identification, and it was not uncommon for ladies of fashion to visithim to ask his opinion on their gems. A collection of precious stones whichhe brought back with him from Europe was sold during his lifetime, andthe gems in his possession at the time of his death were purchased by thegovernment for $2,800 and preserved in the National Museum inWashington.

Another subject of great interest to Leidy was helminthology-thestudy of worms-and flukes and thread worms were often sent to him'byhis fellow researchers.12 In 1847, Leidy made an observation in this areawhich proved to have considerable medical significance: he provided theearliest indication of the source of trichinosis in man. This parasiticorganism had been discovered in humans the previous decade and namedby Richard Owen in London. When Leidy identified some whitish specksin a piece of ham as the cysts of Trichina spiralis, he also had a short-livedeffect on the exportation of American pork. 'Though the most ancient oflawgivers declared swine to be unclean," observes one of Leidy'smemorialists, "it does not seem supposable that he anticipated Leidy andknew that the pigs of his time were infested by this microscopicparasyte."13 The medical implications of the observation were notimmediately so clear as they were later to become. Leidy terminates anotherwise impersonal article on the subject in Pepper's System of PracticalMedicine with the telling remark: "The writer may add that it was in aslice of boiled ham, from which he had partly made his dinner, that he firstdiscovered trichina in the hog."B

Around the time he was appointed to the chair of anatomy, Leidy wasbeginning to be identified with ideas on evolution. With his almostpathological distaste for controversy, and his inability to make enemies,he was particularly hurt by the way his research was used against him forpolitical ends. "All those things which you would think would recommendme to the trustees my opponent is using against me," he wrote to a friendon the subject of his proposed election. "1 am shamefully abused as beingan atheist, an infidel. It has been positively asserted that I seek to makeproselytes to infidelity, and that in my writings I have tried to prove thatgeology overthrows the Mosaic account of the creation. You may judge myfeelings. "15

In preparing The Origin of Species, Charles Darwin was able to drawupon a body of information supplied to him by American investigators,notably his correspondent Asa Gray of Harvard. Fully expecting his book

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to create an unprecedented furor, Darwin documented his theories to thefullest possible extent. Leidy avoided becoming embroiled in the dispute onthis side of the Atlantic in which Gray defended Darwin against vehementopposition from Agassiz. Soon after The Origin of Species was published,however, Leidy wrote to Darwin enthusiastically and enclosed some of hisown papers. Darwin thanked him graciously in a letter in which he wenton to say:

Your note has pleased me more than you could readily believe,for I have during a long time heard all good judges speak ofyour palaeontological labours in terms of the highest respect.Most palaeontologists (with some few good exceptions) entirelydespise my work; consequently, approbation from you hasgratified me much. All the older geologists (with the oneexception of Lyell, whom I look on as a host in himself) areeven more vehement against the introduction of species than arethe palaeontologists.... Your sentence, that you have someinteresting facts "in support of the doctrine of selection, which Ishall report at a favorable opportunity," has delighted me evenmore than the rest of your note.!"

One possible contribution to the theory of species was the materialLeidy had published on the strange case of the American fossil horse.Without theorizing on the subject, he had described remains proving thatthere had, indeed, been such an animal, since become extinct. With thearrival of European settlers, horses were reintroduced, and these proceededto flourish in the environment which had formerly ceased to support theAmerican species. In view of his personal observations, Leidy was morethan ready to accept Darwin's doctrine of selection and, on reading hiswork, he describes feeling "as though I had hitherto groped in the darknessand that all of a sudden a meteor flashed upon the skies."17 Leidyrecommended Darwin's election to the Philadelphia Academy of NaturalSciences which became one of the first institutions to honor him after TheOrigin of Species was published in 1859.

The theory of evolution which Darwin was finally emboldened to printby the threat of being preempted by a rival did not come as a completesurprise to some of the men working in the field. Just such an explanationof life had been making headway in scientific circles, and Leidy himselfhad published remarks of a very similar kind in 1853, six years before theappearance of The Origin of Species and five years after meeting withDarwin in England. In the introduction to Leidy's article, "A Flora andFauna within Living Animals," the author first dismisses the theory ofspontaneous generation which was prevalent at the time. Before treatingthe microscopic organisms which are his subject, he speaks from hisknowledge of geology and paleontology, describing the nature andconditions of life in general:

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The study of the earth's crust teaches us that very many speciesof plant and animals became extinct at successive periods, whileother races originated to occupy their places. This probably wasthe result, in many cases, of a change in exterior conditionsincompatible with the life of certain species, and favorable tothe production of others. But such a change does not alwayssatisfactorily explain the extinction of species.

At this point he refers in a footnote to the American fossil horse. He thengoes on:

Probably every species has a definite course to run in con­sequence of a general law; an origin, an increase, a point ofcumulation, a decline, and an extinction.... Of the life, presenteverywhere with its indispensable conditions, and coeval in itsorigin with them, what was the immediate cause? ... Thereappear to be but trifling steps from the oscillating particle ofinorganic matter, to a Bacterium; from this to a Vibrio, thenceto a Monas, and so gradually up to the highest order of life!

Although fossils provide evidence that the more complicated forms of lifeexisted alongside the simpler organisms, Leidy hypothesizes that "life mayhave been ushered upon earth, through oceans of the lowest types, longpreviously to the deposit of the oldest palaeozoic rocks as known to US! !"18With his aversion to speculation, Leidy attempted to modify his claim forevolution through the expedient of exclamation marks. It is nonethelessclear from this early statement, quoted from a work accepted forpublication in 1851, that Darwin's theories were in accordance withconclusions which Leidy had drawn in the course of his own studies.

In the field of paleontology, Leidy laid the foundation for investigationson a larger scale by ambitious younger men. Othniel Marsh was attachedto Yale's Peabody Museum, an institution endowed by his uncle, while thePhiladelphia Quaker Edward Drinker Cope was a student of Leidy andprofessor of geology and mineralogy at the University of Pennsylvaniafrom 1889 to 1897. With new arrivals in the field, the father of Americanpaleontology found himself squeezed out by these ruthless rivals in the"Battle of the Bones."" Leidy was unable to compete with two men ofindependent means for the specimens which had formerly been sent tohim gratis. He sorrowfully withdrew from the scene of one of the grandscientific controversies of the century which, in the seventies and eighties,embroiled Congress as well as all the major scientific institutions. Concernsfor priority and reputation, most often disregarded by Leidy, soondispelled the courteous tone of the letters in which Cope at first addressedMarsh as "thee." Not long afterwards, he was writing "as a man of honorI request of you ... to correct all statements and innuendoes you havemade to others here and elsewhere."2o

Before Leidy bowed to necessity and removed himself from a field hedescribed as no longer fit for a gentleman, he had added no fewer than 375

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Edward Drinker Cope (1840-1897)by Clarence A. WorrallProfessor of geology and mineralogy andthen professor of zoology and compara­tive anatomy at the University ofPennsylvania (1889-1897). Born inPhiladelphia, Cope entered the Schoolof Medicine b"t dropped his medicalstudies to pursue independent investiga­tions at the Academy of Nat"ral Sciences.He worked at the Smithsonian and with70seph Leidy whom he joined in describ­ing fossils from the Hayden Surveycollected by professor of geologyFrederick Hayden in Wyoming. Theresults of his paleontological and geologi­cal explorations were published in 600articles and books.

genera and species to the 98 previously known." As a teacher of anatomy,Leidy eagerly pursued specimens of a rather different kind to which Cope'sbon mot, "de mortuis nil nisi boneum," seems particularly applicable. Infact, William Hunt attributes the only dishonest action on Leidy's part thathe ever witnessed to the anatomist's desire to supplement the collectionsnow in the Wistar Institute and the Mutter Museum of the College ofPhysicians in Philadelphia. In each collection there is an example of anadipocere body, that is, a body preserved because the degenerated fattytissues have been transformed into a wax-like substance. Two petrifiedbodies from the epidemic of 1793 had been reportedly uncovered at an oldburying-ground which was being cleared for improvements, and, in pursuitof these specimens, Leidy and Hunt went to call upon the caretaker. Thesuperintendent mumbled something about "violated graves," but he addedthat he was able to release bodies to relatives. "The doctor immediatelytook the hint. He went home, hired a furniture wagon, and armed thedriver with an order reading, 'Please deliver to bearer the bodies of mygrandfather and grandmother: " Hunt caps this anecdote with anappropriate rhyme:

So the posters don't worry as to tuum or meum,But take the specimens for the museum.'"

It was not until after the Civil War that an anatomy act governing theuse of unclaimed bodies was passed by the Pennsylvania legislature, andonly many years later were students at last able to do their own dissectionsor to study tissues under the microscope. At the time when Leidy hadreceived instruction from Goddard, ability to use a microscope was stillconsidered an uncommon accomplishment. The instrument with whichLeidy did his later work had only two lenses, and was purchased for thegrand sum of $50. With the emphasis at medical school still on didacticdemonstration, Leidy continued throughout his teaching career to describeanatomical details from the "bull pit" to four hundred students perched onbenches above him. According to one of his most illustrious students,George A. Piersol, Leidy nonetheless provided them with "the first glimpseof a most adequate conception of nature" and sent them forth "with theold fetters of thought shattered for ever."·3 When a department of biologywas established at the University of Pennsylvania, Leidy was appointedprofessor of biology in the faculty of philosophy. A separate faculty ofseven was appointed in 1884, and Leidy then became the first director ofthe biological department, agreeing to give up a professorship atSwarthmore College with which he had supplemented his income forfourteen years.

In addition to the many prizes and honors which he received during hislife, Joseph Leidy was immortalized among the natural phenomena whichhad fascinated him from his earliest youth. On a trip to the Luray Caverns

9.

Professor Koenig's Classin Mineralogy, 1886Black-bearded George Augustus Koenig,professor of mineralogy and metallurgy,taught Towne School students in his"mineral cabinet" in College Hall.Koenig, who held a Heidelberg Ph.D.,was brought to the University af Penn­sylvania at a time when it was alsoattracting faculty trained at Gattingen,Marburg, Tabingen, and other Germanuniversities.

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of Virginia in 1881, his adopted daughter was furnished with a bottlefilled with clear water from one of the pools in the cave. At the appropriatemoment, the torches of the assemblage were held aloft, William Hunt madea brief speech, the bottle was broken, and a column and a stalactite werenamed in Leidy's honor. As early as 1854, the University of Pennsylvaniaalumni, explorers Elisha Kent Kane and Isaac Hayes, discovered two polarcapes on the east coast of Grinnell Land during their arctic expedition andnamed them: Cape Joseph Leidy and Cape John Frazer, the latter for thefounder member of the National Academy of Sciences who becamevice-provost of the University in 1855. In addition, Ferdinand Haydencalled a peak in the Rockies after the scientist whom he had supplied withspecimens in the early years of paleontological investigation. Hunt reportsthat "with the exception of the Tetons, Mount Leidy is the finest object inthe neighborhood, snow-capped and rising in solitary grandeur above theplain."" At the University of Pennsylvania, where a chair was endowed inhis memory in the department of anatomy, his name is inscribed on thebiology building now known as the Leidy Laboratories. Furthermore, thegreat men of medicine whose names decorate the walls of the mainreading room of the Philadelphia College of Physicians begin withHippocrates and end with Leidy.

When the bibliography of this prodigious investigator was assembledby his nephew, Joseph Leidy, Jr., it included some six hundred titles. Notlisted among these serious works is a little book which was read to hisdaughter and nephews at a party in celebration of his fifty-ninth birthday.

PIONEERS OF AMERICAN SCIENCE

It is simply called A Fairy Tale, and it gives an account of the birth of ablue-eyed baby fifty-nine years before and the gifts he received from thefairies. After the usual perfections have been bestowed, "a sweet but gravefairy said 'with these eyes he shall see what man never before has seen;floras and faunas within and without; wings of grasshoppers and how theycan move them, worms of the earth, of man and of cattle, fossils whoseyears are numbered by millions, and to them jelly like drops shall grow torare beauty:"

The fairies come back, fifty-nine fairy days later, to look for evidenceof their gifts. They are greeted by a spectacle which would have frightenedanyone but fairies:

First came the great Hadrosaurus, his years quite a million­"J am his servant, and proud of my master." Next carne theMegalonides and Megatheria, huge creatures, in size like toelephants: then great troops of Wild Horses and herds of WildOxen. "We were long dead, and he gave us new being."

Then, little White Ants, all their Parasites with them.

Then beautiful banners with rare pictures on them; great groupsof Polyps, the CoraIlium leading them. Then wonderfulSponges; and Floras and Faunas; delicate Rhizopods, once meredrops of jelly, and then great leaves of Book Lore, all having thebaby's name on them!'

Joseph Leidy was eminently modest, although he could be eloquent whenspeaking of his discoveries in the naive assurance that his enthusiasm mustbe shared. In the Fairy Tale, his virtue and scientific genius are ascribed tosupernatural powers. Although he had no intention of subscribing to thisview of Leidy's fairy-tale prowess, his memoralist William Huntproclaimed: "Dr. Leidy was a giant in intellect, a saint in disposition."'·

'7

Elisha Kent Kane (1820-1857)Medal by G. H. LovettPhysician and explorer of the Arctic, hereceived his medical degree from theUniversity of Pennsylvania (1842). As anassistant surgeon in the United StatesNavy, he served in China, West Africa,and Mexico, during which time he con­tracted rheumatic fever and typhus whichleft him in poor health. The remainder ofhis short life was devoted to discovery:he went on two expeditions to the Arcticin search of the lost explorer Sir JohnFranklin, commanding the second in hisbrig Advance. He named two capes afterprofessors at the University, and KaneBasin was named for him. At his death,he was regarded as a national hero, andhis body lay in state at IndependenceHall. A lunar crater near the moon'snorth pole was named after him, and asurveying ship, the Kane, was launchedin November 1965.