362 



SCIENCE. 



[N. S. Vol. II. No. 38. 



structed liberally. It will include, with- 

 out doubt, some able scientists and men of 

 liberal education. I may be permitted to 

 cite an occurrence to which some in this 

 audience were witnesses. Some time since 

 the subject of gases in plants was before the 

 Association and induced an animated dis- 

 cussion. Probably half of those partici- 

 pating confounded respiration, which is a 

 general function of all plants, as well as 

 animals, under all conditions of existence, 

 with the photosyntactic function of fixation 

 of carbon by the green parts of plants in 

 the presence of sunlight. Both processes 

 have to do with oxygen and carbon dioxide, 

 but the resemblance goes no further. It is 

 an error dating back to the last century, 

 when the two processes were discovered, 

 and one for which botanists themselves are 

 by no means without responsibility. An- 

 other error not yet dislodged from the cob- 

 webby corners of many a well-read man's 

 intellectual storehouse is the old fiction of 

 a circulation of sap, so dear to those who 

 desire to find analogies in plants with phys- 

 iological processes of animals. It is not 

 much over fifty years since the learned 

 French Academy exhibited its ignorance 

 of vegetable physiology by awarding the 

 grand prize to an essaj^ founded upon this 

 error; and the eiTor still lives. 



But the genei'al ignorance of even the 

 best established and most readily appre- 

 hended facts of physiology may be justly 

 extenuated when the pedagogical status of 

 the subject is examined. Botany, as a sub- 

 stantial part of the curriculum, cannot be 

 said to have received recognized standing 

 in the American educational system until 

 the time of Asa Gray. In the latter part 

 of the decade of the thirties his first text- 

 book, the ' Elements of Botany,' appeared, 

 and in the decade following, the ' Text-book 

 for Colleges ' and the ' Manual,' all of which 

 works showed a true appreciation of the 

 best features of the science and the needs 



of the time. They were so well conceived, 

 and so much in demand, that new editions 

 rapidly succeeded one another ; and to the 

 present day they hold a' high place in the 

 estimation of botanical teachers. These 

 works possessed a speciallj^ potent element 

 of virility in being the expression of knowl- 

 edge at first hand, the words of the master. 

 In so far as inspiration was drawn from 

 foreign sources it came chiefly from French 

 and English scholars, of whom De CandoUe 

 the eldest and Kobert Brown were the rep- 

 resentatives. 



A half century ago vegetable physiology, 

 in the fulness of the modern meaning of the 

 words, did not exist. Structural botany 

 was then the dominant phase, and in ele- 

 mentary instruction took the shape of close 

 attention to the form and arrangement of 

 the organs of flowering plants, with the ul- 

 terior object of being able readily to deter- 

 mine the names of the plants of the field. 

 Even then physiology presented some at- 

 tractive features, but they appeared largely 

 extra-territorial, as the title of the book 

 from which most of us received our early 

 botanical pabulum testifies : ' First Lessons 

 in Botany and Vegetable Physiology,' by 

 Asa Graj', issued in 1857, and continuing 

 its supremacy as a text-book until 1887, 

 when it was revised and renamed. 



In the seventies botanical laboratories 

 began to form a necessarj' feature of the 

 best institutions, each with its quota of 

 compound microscopes and reagents, in 

 which we followed the example of Germany, 

 such laboratories having been established 

 at Halle, Breslau, Munich and Jena a decade 

 previous, and subsequently at manj' other 

 centers of learning. With the advent of 

 Sachs's ' Textbook of Botanj' ' in English 

 dress about this time, the science in America 

 took on a new and vigorous phase of de- 

 velopment. The method of this work found 

 more convenient expression in Bessey's 

 'Botany' (1880), which for a decade was 



