69 



are afforded, the constituent cells produce outgrowths, 

 sometimes presenting the prothallus character, sometimes 

 the frond character, and sometimes an intermediate state 

 in which stomata, a definite frond character, are in close 

 juxtaposition with antheridia, an equally definite feature of 

 the prothallus. At the time of Professor Goebel's report, 

 none of the induced prothalli had produced plants, which 

 he imputes rather to cultural conditions than to incapacity. 

 None of the illustrations show archegonia, and only one 

 antheridia, though in one of these the antherozoids are 

 developed. He anticipates that when a second generation 

 appeared it would probably be an apogamous one ; but 

 since apospory has been shown to be capable of producing 

 perfect bisexual prothalli — A. f.f. Clarissima to wit — in 

 more than one instance, though in most cases the progeny 

 are imperfect and weakly, it is reasonable to expect that 

 like exceptions will crop up when the cultural inducing 

 experiments are extended. 



The practical value of these discoveries to the fern 

 cultivator are not so far obvious, since once the prothallus 

 has produced its primary frond the propagator has attained 

 his object ; but, to the biologist, they are of undoubted 

 importance, as confirming the indication already afforded 

 by apospory, that the line between the two generations 

 represented by prothallus and frond - bearing Fern is 

 more or less undefined, and there is doubtless much to be 

 learnt by such cases as are here concerned, regarding the 

 nuclear conditions of the cell, which determine the subse- 

 quent difference of growth. 



Charles T. Druery, V.M.H., F.L.S. 



