NOTES AND ABSTRACTS. 



309 



This short paper contains a description of the formation of the embryo- 

 sac in preparation for fertilisation, with five figures. — G. H. 



Zamia, Embryology Of. By J. M. Coulter and C. J. Chamberlain 

 (Bot. Gaz. xxxv. No. 3, p. 184, plates vi.-viii.). — The authors describe 

 first the ventral canal cell and egg- cell. No wall is formed between them, 

 and in no case was the former found to be cut off, and it soon disorganises. 

 Their observations on the fertilisation stages confirm those of Webber. 

 After it, there is a period of free nuclear divisions in the proembryo. 

 These were counted to the 256-nucleate stage. 



Then follows the description, with figures, of the differentiation of the 

 suspensor and embryos. 



A series of figures shows the gradual reduction in the number of free 

 nuclei as follows : Ginkgo, Cycas, and Zamia have 256 ; Taxus, 32 ; 

 Podocarpus, 16 ; Thuya, 8 ; Pimis, 4 ; Ephedra, 2 ; and Gnetum has no 

 free nuclear division at all, thus reaching the condition of the embryo - 

 geny of angiosperms, in which the first division of the nucleus of the egg 

 is accompanied by the formation of the wall. 



The paper concludes with a list of works cited. — G. H. 



