46 



BOTANICAL GAZETTE 



[JANUARY 



m< 



view. The same species of variation is also to be observed occa- 

 sionally in inflorescences. 



many 



A glance into two or three private and as 

 herbaria makes it evident that entropic homoeosis is prevalent in 

 ferns. I have found it in the ten species following, repeatedly in 



several of them: 



pidium Thelypteris, A. spinulosum 



lypt 



pi 



Dicksonia punctilobula , Polypodium vulgare, Osmunda 



cinnamomea. 



Among 



these species I have found the phenomenon most fre- 





quently in Polys tic hum (As pidium) acrostichoides, in which species 



its operation takes some 

 interesting turns. The 

 fronds of P. acrosti- 

 choides are somewhat 

 dimorphic, not only in 

 the sense of being 

 soriferous and non- 

 soriferous, but also in 

 the fertile and sterile 

 fronds having slightly 

 different general out- 

 Abnormal pinna of Poly- lines. The sterile fronds 

 stichum acrostichoides. have their apical pinnae 



non-auriculate, obtuse 

 and oblong or elliptical to obovate. In the fertile fronds, 



dimorph: 



shorter, narrower, and abundantly soriferous. 



Homoeotized 



dimorph 



specimens 



herbarium 



J. Winslow, collected in Lowman 



m — r — 



transformed into miniature 



,.._,, - • — fronds. Their 



length and breadth are increased, and the segmentation is quite 

 perfect. One of them very nearly represents a fertile frond, its ter- 

 minal portion being constricted and soriferous, and 



(fig 



many 



Some 



nules, 





















