FERNS, APOSPOROUS AND APOGAMOUS. 247 



the fimbriate projections were remarkably translucent. I 

 obtained material, laid it down, and at once prothalli began 

 to develop vigorously from every point, so vigorously 

 indeed that a single tip has formed a mass of prothalli an 

 inch across which yielded at least a dozen plants of the 

 parental form. 1 



Dr. F. W. Stansfield has recently sent me prothalli 

 developed from a finely fimbriated form of Lastrea of 

 which the reputed parent is that already described, and in- 

 forms me that it is profusely aposporous though fairly de- 

 veloped in size. 



By the various instances of this phenomenon so far 

 cited, we see that the normal life cycles of the ferns in 

 question have been successively shortened, first by the 

 elision of the spore and then by that of the whole soral 

 apparatus, while if we accept De Bary's observations as 

 establishing the constant apogamous reproduction of L. 

 pseudo mas cristata, in that case, it is shortened almost to 

 the utmost, the chain being simply sporophore, prothallus, 

 sporophore. Consistently indeed with the alternation of 

 generation the chain could not apparently be shorter since 

 the prothallus being eliminated we naturally come, or 

 seem to come, to simple bulbils, such as occur on many 

 ferns, Aspleniuvi bulbiferum for example. In the final 

 case, however, which I have to cite, we arrive at the 

 elimination even of the prothallus by substitution of the 

 frond itself as the oophore or egg-bearer, the archegonia 

 and antheridia being generated upon the frond without the 

 prior formation of a prothallus proper. In a small plant 

 of Scolopendrium vulgare recently sent me by Mr. E. J. 

 Lowe, and exhibited by me at the Linnean Society in 

 November last, although a definite axis of growth had been 

 formed and several fronds had arisen in the normal spiral 

 fashion around it, indicating that the prothallus stage had 

 been unmistakeably passed, each of these fronds bore a 

 thickened cushion at its tip upon which were seated both 



1<l Note on Apospory in a form of Scolopendrium vulgare" etc., Linn. 

 Soc. Journal, vol. xxx., pp. 281-84. 



