Makch 26, 1920] 



SCIENCE 



315 



an acquaintance with the details of structure 

 of selected forms. For a knowledge of ani- 

 mals, as members of tasonomic groups, is not 

 lacking in those who pursue zoology in the 

 way I have outlined; and about these animals 

 there is always something besides structure 

 that is worth knowing. In order that these 

 worth-while things may be known adequately, 

 they must be the subject matter of the labora- 

 tory exercises as well as the recitations. 



ISTothing in this article is intended to imply 

 that advanced courses should be of the kind 

 described for beginning students. It is rec- 

 ognized that to become a zoologist, or to pre- 

 pare for certain professions, it is necessary to 

 have a systematic knowledge, not only of 

 taxonomic groups, but of several other fields 

 of zoology as well. In the acquisition of such 

 knowledge there must be courses in which 

 facts seem to outweigh principles. But to 

 attempt to gain such knowledge in the ele- 

 mentary courses, even for those who must later 

 acquire it, is neither necessary nor desirable. 



A. Franklin Shull 

 University or Michigan 



A FORERUNNER OF EVOLUTION 



BICENTENARY OF CHARLES DE BONNET, NATURALIST 

 AND PHILOSOPHER 



March 13, 1920 marks the two hundredth 

 anniversary of the birth of one of the most 

 interesting of eighteenth century scientists, 

 whose researches in entomology and botany 

 were of solid and permanent importance in 

 the history of these branches of learning, and 

 whose philosophy, if superseded, was at least 

 interesting and to some extent prophetic; yet 

 who is comparatively seldom spoken of to-day. 



Charles de Bonnet on that date was bom in 

 Geneva, the sometime home of one against 

 whom he wielded most fiercely his philosophic 

 pen— Jean Jacques Eousseau. Rather curi- 

 ously, de Bonnet's birth and death dates 

 anticipate by an exact century those of a 

 pioneer of evolutionary science, John Tyn- 

 dall. The earlier master died on May 20, 

 1Y93, after a life almost uneventful except 

 for its mental activities. 



One of the most striking facts about de 

 Bonnet's career is the extreme precocity of 

 his talent. His entire work in natural his- 

 tory is crowded into the first twenty-five years 

 of his life; after which failing eyesight, in- 

 duced by close work with the imperfect micro- 

 scopes of the day, turned him perforce from 

 laboratory research to theoretical speculation. 



At sixteen he read Reamur's work on " In- 

 sectology." It proved the turning-point of 

 his life. Bom of a Huguenot exile family, 

 all of whom were accustomed to hold high 

 offices in the Swiss government, de Bonnet 

 was studying law with the expectation of 

 following in the footsteps of his kinfolk. His 

 introduction to entomology ended his interest 

 in law; although he persevered in his studies 

 imtil he attained the degree of Doctor of 

 Laws, he never practised, but devoted the rest 

 of his life to the science which had become 

 his passion. 



Two years after he first read Reaumer and 

 Pluche, he sent to the former a long list of 

 " additions " to his works, based on further 

 investigations. What was Reaumur's aston- 

 ishment to discover that his valuable collab- 

 orator was a boy of eighteen ! By the time 

 he was twenty, de Bonnet had established the 

 fact of at least usual, and probably invariable, 

 parthenogenesis in aphides. Before he was of 

 age, he had been appointed a corresponding 

 member of the Academy of Sciences. Two 

 years later he successfully demonstrated the 

 reproduction of some forms of worms by 

 simple fission; and in the same year he dis- 

 covered the pores, or " stigmata," by which 

 caterpillars and butterflies breathe, and made 

 important studies in the structure of the 

 tapeworm. 



Turning to botany, and newly appointed a 

 fellow of the Royal Society, the youthful 

 scientist next experimented in plant physiol- 

 ogy with special reference to the functions of 

 leaves, and attempted to prove that all 

 ehlorophyllic plants are endowed with sensa- 

 tion and what he termed " discoverment." It 

 was at this stage of his career that threatened 

 blindness diverted his studies into an entirely 

 different field. 



