1907] 



BINFORD— SPORANGIUM OF LYCODIUM 



219 



i 



i 



i 

 I 



(fig. 24) and then by periclinal walls {figs. 25, 26), making a many- 

 celled tapetum of two layers {fig. 27). It is not always dcfmitely two 



layered, as shown in figs. 28 and 2q, 

 When the sporogenous tissue has 

 reached the mother-cell stage, or 

 somewhat before, the inner layer 

 of tapetal cells becomes greatly 

 enlarged {fig. 2g), while the wall of 

 the sporangium rapidly increases in 



Many of the cells of the 

 tapetum become binucleate during 

 this period and the nuclei are to- 

 gether in the end next to the spo- 

 rogenous cells. Finally the inner 

 layer of the tapetum is disorganized 

 and the cytoplasm flows in around 

 the spore mother cells {fig. jo). 



size. 



Fig. 27. 



sporangium 



two-layered tapetum. X480.— FiG. 28.||A section of the sporangium showing a doub- 

 ling of the inner tapetal layer. X480. — Fig. 29. A section showing a further develop- 

 ment of the inner tapetal layer and the beginning of the annulus, r, r. X480. 

 Fig. 30. The spore mother cell stage of the sporangium and the breaking down 

 of the tapetum. X480. 



elopment 



sporo 



The order of 



events is as follows: first a comparatively small amount of growth 



