FERN GROWING 131 



thalli. Other means, however, were also apparent : the tiny 

 offspring of the plant louse, and several other insects, and also 

 minute worms were seen to be constantly moving amongst 

 the prothalli that were covered with a sheet of glass ; 

 whilst confervoid growth and minute mosses made a network 

 between one prothallus and another, and these evidences 

 were pointed out by the author at a time when the diffi- 

 culties to be overcome were reasons given for the sperm 

 being confined to its own prothallus. The question of an 

 occasional submergence of the prothallus by water, which a 

 few drops of rain could accomplish, would be another means ; 

 the sperms would float on the surface, and on this flood 

 subsiding would perhaps find themselves deposited on another 

 prothallus. A consideration of these conditions may assist in 

 explaining why wild varieties are comparatively rare. 



Instead of a single individual having to give his solitary 

 experience, had not death prematurely put an end to a large 

 number of experiments that were being made by Colonel 

 Jones, Mr. Carbonell, Mr. E. F. Fox, Major Cowburn, Mr. 

 Barnard Hankey, and Mr. Clapham, there would have been 

 added much experience and more confirmatory evidence. 

 With regard to Colonel Jones, all his seedlings came into 

 the author's possession, each experiment being numbered as 

 agreed upon, but unfortunately his book of reference could 

 not be found. Mr. Carbonell's plants went to the Royal 

 Gardens, Kew ; but although Mr. Thi^elton Dyer, the Director, 

 kindly sent the author Mr. Carbonell's books, there are no 

 notes that are of any practical service, as they are simple 

 references for his own use. Mr. Fox's books were also pre- 

 sented to the author by his daughter ; in them every experi- 

 ment has been carefully recorded, but they have a vast number 

 of useless remarks stating that confervoid growth, &c., had 

 destroyed the seedlings, and in one instance every experiment 

 during a certain year. Major Cowburn had also numbered his 



