416 REVIEWS. 



that his lately published view admits of more support. It 

 does not govern the division of the cell, as was formerly 

 believed, and Schmitz came independently to the same idea 

 as Strasburger, that the nucleus must have some important 

 duty to perform in the regeneration or increase of proteids. 



The nucleus remains in all cells which have to regenerate 

 or increase their protoplasmic contents, and it disappears 

 last in the living cell. Numerous examples are given, and 

 the author here exercises abundantly his power of concen- 

 trating isolated individual discoveries to the support of his 

 hypothesis ; we must refer the reader to the book itself, 

 however, for the numerous details in this connection. 



As to the penetrability of the cell-wall, the author sets out 

 by remarking that he has little beyond hypothesis to offer. 

 His studies of the cases where protoplasm passes from cell 

 to cell through tiipfel, canals, &c., in the walls, and com- 

 parisons of what others have done, lead him to believe that 

 the protoplasm of the cells in a plant may be continuous by 

 means of extremely numerous fine filaments even where too 

 delicate to be observed. It is in such connections as this 

 that Prof. Strasburger exhibits to the full his daring and 

 ingenuity in the wide field of hypothesis. As we have 

 shortly indicated, one fifth of the present book consists in 

 great part of brilliant speculations. If the author were not 

 so well known as an indefatigable and accurate observer, 

 such attempts to extend our sphere of knowledge by hypo- 

 thesis would probably receive less attention than they 

 deserve ; as it is, no biologist will undervalue the wildest 

 thoughts of the author of ' Zell-bildung und Zell-theilung,' 

 and we can honestly welcome the present book as a valuable 

 acquisition to the literature of the cell theory, perhaps con- 

 gratulating ourselves that the composition and literary 

 ability displayed do not constitute the most forcible battery 

 of Prof, Strasburger's logical artillery. 



Recent Researches on the Cilio-Flagcllata. By Professor 

 T. Jeffery Parker. 



This interesting group of Infusoria has lately received 

 the attention of a Danish zoologist, Mr. R. S. Bergh, who 

 publishes an elaborate monograph on the subject in the last 

 number of Gegenbaur's ' Morphologisches Jahrbuch.'^ 



' R. S. Bergh " Der Organismus der Cililoflagellaten, eine phjlogene- 

 tische Studie." ' Morpb. Jalub.,' Bd. vii, 2 Heft, pp. 177-288, pi. xii-xvi. 



