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POPULAR SCIENCE MONTHLY. 



from others. The plants throve, and the fruit was abundant and 

 filled out, but when half ripe they began to dry up, and not one 



produced perfect seeds. His com- 

 munication on this subject is 

 dated December 28, 1691." The 

 importance of his discovery was 

 not recognized at the time, and 

 his conclusions were accepted in 

 a figurative sense only. Not until 

 the end of the following century 

 was his experimental evidence 

 used as a basis for further re- 

 searches by Kolreuter. Linnseus, 

 to whom great credit is given by 

 many writers for his share in the 

 development of the theory of the 

 sexuality of plants, ignored the 

 facts disclosed by Camerarius, 

 and arrived at identical conclu- 

 sions in a purely deductive man- 

 ner, arguing from the necessities 

 of the case. 



After the demise of Camera- 

 rius he was succeeded by his son 

 Alexander. Later the lectures on 

 the subjects of botany and chem- 

 istry were given by one professor. 

 After a short interregnum the subject was once more in the hands 

 of a master spirit in the person of Joseph Gaertner, who was 

 called to the chair of botany in 1760. Gaertner remained at Tubin- 

 gen eight years, going to St. Petersburg to accept the chair of 

 botany in 1768. He returned to Calwe in 1770, and published 

 shortly afterward his De Fructihus et Seminibus Plantarum, 

 which may be truly termed an epoch-making work. The study 

 of fruits and seeds had languished for more than a century, and 

 Gaertner came to it with a mind singularly free from prejudice. 

 He was aware of the real value of fruits for the arrangement of 

 plants in a natural system, but he did not attempt to found a 

 system on such material alone. Having at hand a most extensive 

 collection of plants from around the world, which he studied with 

 a persistence that brought him nearly to blindness, his book is an 

 inexhaustible mine of facts and a guide to the morphology of 

 fruits and seeds. His collection of material and microscope are 

 still preserved in the botanical museum. 



The lectures in botany at the university were placed in the 

 hands of Friedrich von Kielmeyer as professor of natural phi- 



WiLHELM Pfeffer, Professor of Botany and 

 Director of the Botanic Institute, 1878- 

 1887. After a photograph by W. Hor- 

 nung, Tubingen. 



