1 96 THE HISTORY OF BIOLOGY 



applied himself to botany, which had always interested him. In order to be 

 able to earn his living he started by taking the degree of doctor of medicine. 

 His botanical works soon gained him a wide reputation; he was appointed 

 professor at the Jardin des Plantes in Paris and had an opportunity of making 

 many long journeys for research purposes. He died in 1708 as the result of an 

 accident. 



In the introduction to the important botanical work in which he sum- 

 marized the results of his research activities he expounds his principles of 

 plant classification. He defines the plant as an organic body, which always 

 possesses roots, practically always seeds, and nearly always stalk, leaves, 

 and flowers. He bases his ideas of the structure of plants on Cesalpino and 

 Malpighi. When later it comes to classifying and giving characters to plants, 

 he maintains, under the manifest influence of Cesalpino, that only the flowers 

 and fruits can come into question; he seeks far and wide for proofs as to why 

 root, stalk, and leaf do not provide reliable characters. In particular, the 

 plant genera should be based on similarities in the structure of the flowers 

 and fruits, but as the same genus includes forms whose remaining parts are 

 different, so the genera must in their turn be divided into sub-categories. 

 Tournefort pays great attention to his description of the genera, and his 

 diagnoses of them are often so striking that subsequent systematicians, up 

 to our own time, have been able to accept them, though they are only based 

 on the characteristics of flower and fruit; on the other hand, the "species" 

 into which the genera are divided are mentioned with only a few words 

 regarding the form of the stalk and the leaf, without any further description. 

 His method of procedure is thus the exact opposite of Bauhin's. But over and 

 above this, Tournefort works out for the first time a systematic classification 

 of categories higher than the genera — that is to say, he divides the plants 

 into a number of classes, which again are severally divided into sections; 

 each of these is characterized in a few words, but is not given a name. The 

 characters of these higher categories are derived from the peculiarities of the 

 flower; several categories of flowers which still to some extent hold good 

 today are determined by him: with and without corolla, with or without a 

 gamopetalous corolla, and, again, cruciform, Ungulate, and other flower- 

 forms. The division into herbs, bushes, and trees abolished by Rivinus he 

 himself, however, was never able entirely to reject; his system comprises 

 seventeen classes of herbs and five classes of bushes and trees. With regard 

 to anatomy and physiology Tournefort has not much to ofi'er that is new; in 

 the course of his journeys he had observed the artificial fertilization of date- 

 palms practised in very remote periods and already described by Theophras- 

 tus. They are, as is well known, both male and female, and the cultivators 

 facilitate fertilization by suspending male clusters over the females, but 

 Tournefort is unable to derive any theoretical conclusions of importance 



