Record. lv 



starting point in the synthesis of ionone, the artificial violet 

 perfume. 



The wonderful progress in our knowledge of the terpenes 

 and of their derivatives is the work of scarcely more than ten 

 or fifteen years. There is great activity still, and among 

 those chemists who have taken a prominent part in the labor 

 should be mentioned Wallach, Baeyer and Tiemann. 



Dr. Sidney I. Schwab, of St. Louis, Professor S. Calvert, 

 of Columbia, Missouri, Professor George Hazen French, of 

 Carbondale, Illinois, Professor David M. Mottier, of Bloom- 

 ington, Indiana, Professor W. J. Stevens, of Carthage, Mis- 

 souri, and Professor Frank Thilly, of Columbia, Missouri, 

 were elected to active membership. 



Eight persons were proposed for active membership. 



April 16, 1900. 



President Engler in the chair, twenty-three persons present. 



Mr. Herbert F. Roberts addressed the Academy on the 

 structure and physiology of the cell in the plant organism. 

 The history and development of cytology as a special field in 

 biology was traced, and the origin of the various theories of 

 cell organization was indicated. The development of various 

 theories respecting the centrosome and its role in cell division 

 was discussed, the homologues of the centrosome to be found 

 in ciliated cells and spermatazoa being indicted. After a 

 review of the processes of cell division and their attendant 

 phenomena, the methods of study of mitoses in plants and their 

 proper illustration was considered. A great need exists for 

 more accurate processes of reproduction than is afforded by 

 plates made from camera lucida drawings. The latter are 

 always more or less diagrammatic, and are apt to be modified 

 by the personal bias of the investigator. Unconsciously the 

 personal equation enters in. This is seen in recent work on 

 the existence of the centrosome in higher plants. The diffi- 

 culty referred to can be overcome by the employment of 

 photomicrography. This has been made use of to a limited 

 extent by zoologists in the study of mitoses, but apparently 

 scarcely at all by botanists. The speaker showed forty prints 



