88 Cytologie und Befruchtung. — Descendenz und Hybriden. 



Geschlechts-Kernsubstanz" nachzuweisen sein wird, woran 

 natürlich die Thatsache nichts ändert, dass für gewöhnlich beide 

 in einem Kern vereinigt sind. „An diesen neuesten Gesichts- 

 punkten^ die für die Prolozoen-ZeWe gewonnen wurden , kann 

 auch die zünftige Cytologie nicht vorübergehen.'' 



Tischler (Heidelberg). 



MOTTiER, David M., Fecundation in Plauts. (800 p. VIII 

 -|- 187. 75 figures. Published by the Carnegie Institution 

 of Washington. 1904) 



In this book Prof. Mottier treats the problem of fecun- 

 dation by discussing concrete cases, usualiy selecting the most 

 thoroughly investigated forms. Fecundation is a problem of 

 the cell and more particularly a problem of the nucleus. The 

 work is not confined to the actual process of fecundation but 

 considerable emphasis is laid upon the development and diffe- 

 rentiation of gametes and upon the subsequent behavior of the 

 fecundated egg. Genuine sexual acts are carefully distinguished 

 from vegetative nuclear fusions. In arranging the material, 

 the author has had in mind no particular theory of the origin 

 of sexuality, but merely the idea of the evolution of the plant 

 kingdom and the corresponding differentiation of the sexual 

 Organs and cells. The numerous theories bearing upon the 

 subject are not discussed but theoretical matters are touched 

 upon chiefly to suggest lines of investigation. In matters be- 

 longing to the authors particular field he has expressed his 

 views freely. 



The introductory chapter deals with nuclear and cell divi- 

 sion, the centrosome and blepharoplast, the significance of the 

 sexual process and the numerical reduction of chromosomes. 

 The remaining chapters are as foUows: II. Fecundation; Motile 

 Isogametes. III. Fecundation ; Non-motile Isogametes. IV. Fe- 

 cundation; Heterogametes. V. Type of the Ascomycetes and 

 Rhodophyceae. VI. Arche goniates. VII. Angiosperms. 



While Prof. Mottier 's experience in cytological matters has 

 enabled him to make a large and judicious use of the resulis 

 of other investigators, the work must not be regarded as a 

 mere compilation, for the authors own results and views are 

 evident throughout. Charles J. Chamberlain (Chicago). 



GiLLOT, F. X., Sur une variete de Houx commun (Hex 

 Aqulfoliiim var. ancnbiformis). (Rev. de Bot. System, et de 

 Geogr. bot. T. II. 1904. p. 135—140.) 



Sous le nom de var. ancnbiformis, l'auteur decrit une variete d'Ilex 

 Aquifolinm, des coteaux du Charollais et du Brionnais, differant 

 du type ou var. vulgaris par des tiges plus fortes et plus elevees_, des 

 feuilles plus larges et surtout des fruits plus gros et ovoVdes. 



' ^ ' " J. Offner. 



