162 THE AMERICAN NATURALIST [Vol. XLII 



protkallia of the various ferns referred to shows some 

 differences which are probably not without significance. 

 The structure of the mycelium and its general behavior 

 are so much like those of the endophyte occurring in the 

 strictly saprophytic gametophyte of the OphioglossaceaB 

 as to leave little doubt that the endophyte in each case 



is the same, or at any rate closely related. The conidia 

 (Fig. 3, A, C) are perhaps less frequent, but in form 

 and structure are very like those of Botrychium. The 

 most noticeable difference is the apparently complete 

 absence of the " digestive" cells, i. e., those that contain 

 the varicose swollen mycelium. No indications were 

 noted of the destruction of the fungus by the cells of the 

 host and the former is evidently much more nearly a 

 true parasite than is the case in the saprophytic gameto- 

 phytes. In the infested cells of the green gametophyte 

 the starch and chromatophores are destroyed evidently 

 by the action of the endophyte, but the nucleus remains 

 intact. 



