The Evolution of Botany. 179 



cupied himself very successfully with phytotomy plant 

 anatomy of which he was one of the founders. He dis- 

 covered the cell-structure of plant tissue, distinguished the 

 parenchyma tous tissue from the longitudinal fibers, the wood- 

 bundles and ducts, and studied more carefully the relations 

 which these cell-forms bore to each other in the various 

 organs of the plants. His investigations brought to light 

 much that we now know of spiral ducts. His book Anatomy 

 of Plants, published in London in 1682, was an excellent work 

 in that time. Leeuwenhoek, too, did much in developing 

 microscopic botany. He was, at the time the microscope 

 was invented, a modest book-keeper and cashier in an 

 Amsterdam clothing-house, but he became so much interest- 

 ed in the new instrument that he set about manufacturing 

 it for his own use, and making investigations therewith. 

 Aside from the many discoveries he made, which widened 

 the knowledge of human anatomy, the discovery of the 

 spotted, spiral, and scalariform ducts in plants is ascribed to 

 him. He was the first to point out the difference in structure 

 between the monocotyledonous and dicotyledonous stem 

 i. e., the difference in stems of trees exemplified by the palm 

 and oak. These discoveries were made with microscopes of 

 his own make, of which he possessed about 200, in manu- 

 facturing which he displayed much skill and ability. If 

 this enterprising Dutch investigator had had a good educa- 

 tion, so that he would have worked systematically, he un- 

 doubtedly would have contributed even more to the advance- 

 ment of botany than he did. 



This period is followed by one in which classification re- 

 ceived renewed attention, this time by Morison, Ray, Herr- 

 man, Boerhaave, G. A. Rivinius, and others. Ray, 1703, and 

 Morison, 1715, accepted Caesalpinius's arrangement, which 

 they supported and developed more fully. The latter in- 

 cluded in his method the formation of the floral envelope 

 and its parts. Rivinius, earlier than that (1690), employed 

 as standard for his system the regular or irregular form of 

 the perianth or floral envelope. 



An important progressive step in descriptive botany was 

 made also, at this time, by Tournefort. He was professor 

 of botany at the botanical garden at Paris, whence he was 

 sent by the French Government to Greece and Asia Minor 

 to study the floras of those countries. He spent two years, 

 1700-1702, in botanical explorations, and brought back 

 with him representatives of 1,300 new species. He also 



