478 



BOTANICAL GAZETTE 



[JUNE 



A number of forms were found in the culture which were inter- 

 mediate in character, as shown by fig. ii. This growth resembled 

 the leaf of an ordinary sporophyte. Typical epidermal cells 

 including stomata, always present on the lamina of a leaf, were 

 absent in this instance. No structure resembhng a root was 

 present. Fig. 4 shows the terminal portion of the lamina-like 

 part. 



An effort was made to study the nature of the development of 

 the prothalloid portions from the earliest stages. The earHest 



stage found was one 

 composed of 4 or 5 

 cells, formed in connec- 

 tion with the petiole of 

 the primary leaf. For 

 several days the growth 

 was followed and 

 during that time a 

 number of cells had 

 been produced, as 

 shown in fig. 1 2 . When 

 the earliest stages were 

 observed the leaf had 

 already emerged from 

 the pro thallium, and 

 distinctly gameto- 

 phytic cells could then 

 be seen. Since the 

 number of instances 

 of apospory appearing 

 in the culture was not large, as compared with the number of 

 sporophytes, a favorable opportunity to study the stages in sec- 

 tions was not offered. It is certain that such forms represented 

 by figs. 8 and 16 were never wholly sporophytic and later became 

 gametophytic. From such an instance as shown in fig. 5, how- 

 ever, it could readily be conceived that the prothallia developed 

 from the primary leaf which was distinctly sporophytic in 

 character. 



Fig. 4. — Terminal portion of leaflike structure of 

 Pkris sulcata; X322. 



