FERNS, APOSPOROUS AND APOGAMOUS. 245 



the further investigation of the case, and found that the 

 development of the sorus or spore heap went as far as the 

 formation of the stalk of the sporangium or spore capsule, 

 but at that stage it stopped and a vegetative growth set in 

 to form the clusters of pear or club-shaped bodies which 

 eventually went through the normal evolution of prothalli 

 and sexual plants. Mr. G. B. Wollaston followed by 

 providing material from a variety of Polystichum angulare 

 in his possession, wherein the elimination of the spore and 

 the entire soral apparatus was so complete that the prothalli 

 were developed from the slender-pointed tips of the ultimate 

 divisions of the fern-frond. Padley, P. ang. var pule her rinmm 

 was the plant in question, and as it chanced that several 

 other varieties of the same type existed, though found at 

 widely sundered spots in England, it resulted that Dr. 

 F. W. Stansfield and myself found the same character in 

 two of them. Prof. Bower further observed that soral 

 apospory, i.e., the form first noted, was also present on 

 Padley's plants, and this too we, Dr. Stansfield and my- 

 self, confirmed in the others. We have in these four 

 examples, and in the genus Polystichum especially, ample 

 proof that the spore is not an essential preliminary to 

 the existence of the Prothallus, but that the latter may 

 be developed direct from the tissues of the Sporophore, 

 precisely as this latter in Apogamy may be developed 

 direct from those of the oophore. 1 Curiously enough 

 the next case which came before the writer's notice 

 was an aposporous seedling of the same variety of Lastrea 

 (Aspidium) determined by De Bary as being persistently 

 apogamous, viz., Lastrea pseudo ?nas var. cristata. This 

 case was distinct from previous ones as it was a young 

 plant and not an adult, which produced the prothalli. The 

 tip of the second frond evolved from the prothallus (the 

 first was eaten off and was not seen) bore a prothallus of 

 the normal form. Subsequently this and the succeeding 



1 Professor F. O. Bower subsequently prepared an exhaustive mono- 

 graph "On Apospory and Allied Phenomena". Linnean Transactions, 

 vol. ii., part 14, July, 1887, to which reference should be made for details 

 of the preceding cases. 



