474 BOTANICAL GAZETTE [june 



and mounted in glycerine jelly. Some of the drawings were made 



from living material. The sporophyte tissue is represented in the 



drawings by the darker shading; the gametophyte by the lighter 



shading. 



Observations 



The gametophyte of Pteris sulcata produced by the germination 

 of a spore is in many respects similar to* that of Pteris cretica var. 

 alho-lineata described by Farlow (ii) and DeBary (i). • When 

 the prothallia of both species were grown under the same cultural 

 conditions, it was observed that those of the former were somewhat 

 larger. Archegonia were never found on any of fhe large number 

 of prothalha carefully examined with the microscope. Antheridia 

 occur commonly and frequently in great abundance. The anthero- 

 zoids are apparently normal in every respect. 



The embryo of Pteris sulcata is always produced apogamously. 

 Such a development of the embryo was first described by the 

 writer (21). Suminski (22) and later Mercklin (16) observed 

 tracheids in the prothalha of this species just posterior to the apical 

 notch. DeBary grew the prothalha of the same species, but 

 observed no sporophytic tissue elements or any other indications 

 of a sporophyte of apogamous origin. Accordingly he reported the 

 fern as non-apogamous. The writer, however, has found the fern 

 to be constantly apogamous under normal cultural conditions. 

 From the sporophytes apogamously produced the gametophytic 

 developments herein described appeared. 



In every instance in my culture the prothallial portions or 

 prothalha were produced in connection with the lamina or the 

 petiole of the primary leaf. Usually the terminal portion of the leaf 

 was in part or wholly prothalloid. Occasionally forms were 

 observed which were intermediate in character, the cells partaking 

 of the nature of both sporophyte and gametophyte. Sometimes 

 root, lamina, and petiole of the sporophyte were formed (fig. 13). 

 In some instances the root was absent (figs. 6, 8), and in still other 

 cases only a well developed petiole was present (fig. 8) , the lamina 

 of the ordinary leaf being displaced by a prothalloid portion. The 

 vascular system in the primary leaf as a rule was well developed. 



