xvi] 



APOSPORY 



321 



sporophytic buds from the cushion of the prothallus of Pteris cretica, without 

 the intervention of sexual organs. The subject received more general treat- 

 ment later by De Bary (1878), who introduced the term apogamy to include 

 all cases of the elimination of the sexual function (Fig. 296). The converse, viz. 

 the omission of the event of spore-production, was first demonstrated by 

 Druery before the Linnaean Society in June, 1884, and later it was examined 



Fip;. 296 continued. C=the initiation of a prothallus as in B, at the apex of a pinnule. The shading 

 indicates a vein, beyond the tip of which the prothallus arises. ( x 130.) Z> = a similar growth, but 

 borne on an elongated cylindrical process : archegonia [arch] are already present. ( x 10.) E — ^ox3.\ 

 apospory in Polystichum angulare, vav. pulchen-iimim. A prothalloid growth bearing an antheridium 

 (anth) and rhizoids {/i) has arisen from the stalk of a sporangium. ( x 70.) 



in greater detail by myself in the Proceedings and Transactions of the Society. 

 The term apospory, previously introduced by Vines, was adopted to connote 

 all such cases (Fig. 296). Since 1884 very many observations both of 

 apogamy and of apospory have been published, relating to very different 

 families of Ferns, but chiefly to those which are phyletically late and deriva- 

 tive. Thus the phenomena which at first were held to be rare are now seen 



