mj-:r/l\l\ \.i fCA'.i /./sr. [X'oi.. xxxviii. 



•iropnalcd ms a iKirl ot tin; L;ametophyte 



cse three l\]X's ot ciiil)r\()-siic development 

 )cess ot which the tlurd stai;e is plainly 



and very complex condition, far removed 

 'tophvte structures amoni;- the anfjiosperms. 

 t these iorms ( Lilium, 1 ulipa, iMitillana, 

 re probably the most complex spore mother- 

 V I he studies of Schniewmd- 1 hies and 

 supported bv other ]n\ esti<;ations. and more 

 csults ot J m^l ( OJ) on Pans quadntolia 

 difiontm, who iollowed the history of the 

 mot) pit mitoses in these foims in detail 



second type of embryo-sac development m 



Schniewind-Thies. 



n m the embryo-sac mother-cell has not 

 ention as m the pollen mother-cell, ]:)robably 

 the latter structures may be obtained much 

 the former. 1 here have been numerous 

 ires of the spindles but tew accounts m full 

 nt. Of the latter the investigation of 

 .ihiim IS the most complete. 1 his paper was 



■ when the centrosome question was under 

 ed. with other papers on the spore mothei- 



. luel, 97, Mottier, 97) to discredit the pres- 

 •s m this structure. Mottier found that the 

 • \ o-sac became invested with a close network 

 ■) Ironi wluch fibers developed into the cyto- 



'H ot tlie nuclear membrane the tibrilhie 



■ cavitv, tilhn-- it with masses ot fibers which 



cones luei u.me to^ahei into two poles, 

 UK spindle the hbi ilh ue ticquenth m se\ ■ 



i\ large number ot later i)apers have 



