8 Britton and Taylor : Life History of Schizaea pusilla 



not appear on the sporophyte until the first leaf has reached a 

 height of I mm. It resembles the one referred to by Bower in his 

 work on Trichomanes. No connection has yet been made between 

 these hyphae and those of the fungus symbiont. As far as is 

 known at present, the fungus which wraps itself around the pro- 

 tonemal filaments is the same or at least bears a very close resem- 

 blance to that which attacks the sporophyte both on the rhizome 

 and leaf. 



The hyphae of the symbiotic fungus penetrates the rhizoid 

 generally a short distance back from the tip (Fig. 41, <r). These hy- 

 phae sometimes branch in the rhizoid and their cross-walls are 

 more numerous, and in many cases the hyphal threads appeared 

 narrower. They enter the large spherical cells where they form 

 bladders or granulated swellings in these cells, sometimes nearly 

 filling them (Figs. 42, 43). The fungus sometimes penetrates the 

 ordinary cells of the filament, entirely changing the shape of these 

 cells. Pale brown bodies were found of irregular outline attached 

 to the hyphae which were apparently sporangia. 



Antheridia 



The antheridia are produced laterally on the protonema, occu- 

 pying the terminal cell of the lateral branch or more rarely the 

 terminal cell of a filament, which continues its growth laterally 

 or ends with the formation of the antheridium. They are found 

 either singly or in groups ; and may be considered as metamor- 

 phosed branches as in Fig. 44. They may either be formed from 

 the terminal cell of a short lateral branch (Fig. 44) or from the 

 terminal cell of a branch giv^en off from the basal cell (Figs. 44, 

 48) or from the second or any other cell of a lateral branch (Fig. 

 44) or rarely they may be formed on the terminal cell of a short 

 lateral branch given off from the same cell of the filament as a 

 previous antheridial branch (Fig. 46). Occasionally these groups 

 are borne on a branch of the filament which bears only antheridia 

 (Fig. 48) and for the most part in groups, sometimes from both 

 sides of a branch. These branches which bear the antheridia, 

 whether it is a branch of two cells with the apical one becoming 

 an antheridium, or one of the groups, occupies the same relative 

 position on the filament as do the branches of the main filament. 



