Allgemeines. — Cytologie u. Befruchtung. 259 



devotes about twenty pages to the Classification of the Schizomycttes, 

 so that the chapter is really the same in nature as those on „The Algae", 

 „Fungi" and the other groups. 



Chapters four to twelve inclusive may be considered taxonomic in 

 nature, the material being arranged in Orders and sometimes Families, 

 largely according to Engler and Prantl's „Natürliche Pflanzen- 

 familien". Considerable morphological material is inserted, especially in 

 the introductions to the larger groups. 



In the Chapter on Physiology, „the materials are drawn largely from 

 the works of Sachs and Pfeffer, the recent physiological text-book of 

 Professor Pfeffer being used as a basis". 



In a work purporting to present „the essentials of modern botany", 

 the histologist certainly has a right to expect the most important features 

 in his field. The almost entire Omission of the most important micro- 

 chemical reactions may possibly be excused on the ground of the work 

 not being a laboratory manual. At the same time, it is certainly questio- 

 nable if some indication of some of the characteristics of substances as 

 revealed by reagents is not essential in a work of reference. An intelli- 

 gent College Student who turns to the book for Information on starch 

 will be disappointed. The account of Aleurone is meagre. The only 

 Information concerning tannin is that it is found with other organic acids 

 in Solution in the vacuoles of Zygnetna, and that „small, bright drops 

 (tannin vescicles)" are characteristic of many species of Conjugatae. 



Thirty-three pages might to some seem insufficient for the presen- 

 tation of the essentials of modern vegetable physiology, while the Biologist 

 has probably less reason to feel aggrieved at the devotion of the 66 of 

 the 579 pages to the „Relation to Environment". 



In the final chapter on „Geological and Geographical Distribution" 

 are included, in addition to other material, some which might be treated 

 by some writers under Physiographic Ecology. First, the author dis- 

 cussed briefly the geological distribution of Thallophytes, Bryophytes, 

 Pteridophytes, Gymnosperms and Angiosperms. This is followed by a 

 section on „Factors influencing the Distribution of Living plants". The 

 distribution of the flora of the United States and especislly of the Pacific 

 Coast and California are treated in a brief way. 



The book is illustrated by 15 plates and 493 text figures, zinc 

 etchings, mostly from drawings by the writer. It must be said that the 

 execution might have been better. • J. A. Harris. 



OSTERHOUT, W. J. V., Cell S tu dies. I. Spin die formation 

 i n Agave. (Proceedings of the California Acad. of Sciences. 

 Ser. III. Vol. II. 1902. p. 255—284. Pls. 25—28.) 



In this work considerable attention was given to technique, 

 especially to fixing. About forty fixing agents were tested by 

 watching their effect upon the living cell and it was found that 

 some of the most highly recommended Solutions produce pro- 

 found disturbances in the cytoplasm. For most objects fixing 

 agents were found which produced no visible change in the 

 living cell, as far as could be observed with a 2 mm oil 

 immersion lens during the application of the reagent, but even 

 in some such cases the material undergoes structural changes 

 after a few hours and the time must be shortened accordingly. 

 Flemming's strong mixture proved to be the best in most 

 cases; very fair results were obtained with iridium Chloride, 

 platinum chloride, palladium chloride, and Fl em mi ng's strong 

 mixture with an excess of chromic. Material was washed from 

 two to eight hours in running water and then dehydrated. 



17* 



