86 



The An the rid ill m. 



Rauwenhofi'' studied tlie structiu-e and development of the 

 antheridia in several species of (ilelcheidd, especially G. rapc.strls. 

 All of the species studied by him agree closely in the structure 

 of the antheridium and differ only slightly in this respect from 

 the Polypodiaceae. Of the species considered in the present 

 paper G. polypodloides comes nearest to the species examined 

 by Rauwenhoff. The other species show very marked differences, 

 especially in the very much larger size of the antheridium, 

 this being especially noticeable in G. pectinata and (t. lacvit/ata, 

 the former of which was studied in detail. The aiitheridia as 

 we have seen occur in this species upon the lower side of the 

 wiugs of the prothallium and also upon the sides of the midrib. 

 In the species studied by Rauwenhoff there is a cell cut off* 

 from the base of the young antheridial cell forming a stalk- 

 cell of greater or less size, and in G. pectinata this is often 

 followed by one or more later ones intersecting the first cell 

 so as to form a stalk of greater or less length (PI. X, Fig, 64). 

 According to Rauwenhoff there is then formed a wall similar 

 to the funnel-shaped one found in the antheridium of the 

 Polypodiaceae. I have not found this wall in any of the species 

 examined by me. Instead of this there are two or more curved 

 walls that are formed in succession somewhat after the fashion 

 of the segments of the apical cell. In this respect as well as in 

 the later stages of the antheridium it is similar to that of Osmiuida 

 (PI. XI, Figs. 70 and 71). 



Cross sections of young antheridia of G. pectinata showed two 

 or three of these intersecting walls enclosing the central wall. 

 From the latter by a more or less curved periclinal wall (PI. X, 

 Fig. 65) there is separated a central, approximately tetrahedral 

 cell from which the spermatocytes arise. In his Fig. 58, repre- 

 senting a young antheridium, Rauwenhoff shows chlorophyll- 

 bodies in tlie central cell. It is probable that the specimen 

 figured is abnormal, or that the chlorophyllbodies shown belong 



