192 



and in every case apical apospory was found to be corre- 

 lated with it, and furthermore soral apospory existed on 

 the fertile fronds. The modifications of the life cycle, 

 however, were not even yet exhausted, for curiously enough 

 a sporeling of the apogamous variety of Lastrea above- 

 mentioned was found by the writer to bear a well developed 

 prothallis at the tip of its first frond, and the second and 

 third bore prothalli, even profusely, on their surfaces, a 

 sort of prothallic rash as it were.* These produced a. 

 brood of plantlets, but one and all lost this aposporous 

 character and assumed the merely crested type of the 

 parent as their later fronds arose. Here as we have 

 apogamy and apospory associated, the life cycle dwindles 

 down to the sporophyte, prothallus, sporophyte, the 

 shortest possible cut except the bulbils on the fronds of vivi- 

 parous ferns, which have no intermediate stage at all. Sub- 

 sequently, the writer found both soral and apical apospory 

 on another variety of Athyrium, and apical on a fimbriate- 

 form of Scolopendrium.t Curiously enough, subsequent 

 to the discovery of the aposporous Lastrea, a sporeling of 

 the same parentage originated in Mr. Cropper's collection, 

 which was and is profusely prothalliferus from all apices, 

 the smallest piece of frond forming a mass of prothalli 

 when layered, which creeps about Marchantia-like and 

 yields a perennial crop of typical plants. Finally, in this 

 connection, Professor Farlow found an aposporus (soral) 

 type of Ptevis aquilina. Subsequently, at Professor F. O. 

 Bower's suggestion, Mr. W. H. Lang commenced a series 

 of investigations in connection with the prothalli produced 

 from spores of abnormal varieties, and thereby practically 

 completed the series of abnormal modifications of the life 

 cycle, by finding in more than one species prothalli 



* Druery, C. T. : Jour. Linn. Soc. 29 ; 480-482. 1892. 

 t Druery. C. T. : Jour. Linn. Soc. 30 : 281-284. 1892. 



