24 



MORPHOLOGY OF SPERMATOPH i'TES 



daughter cells divide in the usual way, and heavy walls are 

 again formed. Within this heavy four-celled and often lobed 

 case the microspores are organized. 



The first comparatively full account of the germination of 

 the microspore seems to have been that of Juranyi ^ for Cera- 

 tozamia longifolia. In 1896, in a preliminary paper,2o fol- 



:4|^ 



/ 



Fio. 22. — Cfycas revoluta, development of the ciliated male cell: .1, male gametophyte 

 of three cells, vegetative or '' prothallial " cell (^), generative cell, and tube cell (^), 



X 500 ; B, the generative cell (a) rounded off, x 200 ; C, the generative cell (a) show- 

 ing division of nucleus into stalk and body nuclei, x 500; D, fii-st appearance of 

 blepharoplasts in enlarging body cell (6), and diminishing stalk nucleus (s), x 500 ; 

 £, body cell (b) shortly before division, showing well-developed blepharoplasts (c), 



X 750 ; F^ the two male cells resulting from the division of the body cell, showing 

 the beaked nuclei, x 200; ff, //, /, later stages in the development of the ciliated 

 male cell, x 200. — After Ikeno. 



lowed by the full paper -" in 1S9S, Ikeno presented a detailed 

 account for Cycas rerohita ; while in 181)7 Webber -•''- *"' -^ pub- 

 lished his results for Za))}ia integrifoJia. One of the authors 

 has also examined ]\lr. Webber's preparations. The sequence 

 of events is as follows (Figs. 22, 23) : 



A small lenticular cell is cut off and persists, and as it seems 



