43 MEMOIR OF DR. HARVEY. 



I dined yesterday with Mr. Ward, a botanist not perhaps 

 unknown by thee. He is very zealous and ingenious, and has 

 an herbarium of about 25,000 species. He is particularly fond 

 of ferns, and indeed of all Crypts. He has been trying experi- 

 ments in cultivating ferns and mosses, and in the former has 

 succeeded to admiration. He finds that many stove ferns suc- 

 ceed in the smoky atmosphere of Tower Hill, and require far 

 less heat than is generally supposed to be necessary for them. 

 In fact he gives them no artificial heat at all. His plan is to 

 keep them in an excessively moist atmosphere, by preventing 

 the escape of vapour. He actually grows them in glazed boxes 

 hermetically sealed, and leaves them undisturbed for six or 

 eight months together. Nothing could flourish better than 

 those I saw. In those sealed boxes he has had some excellent 

 parcels of live ferns from Van Diemen's Land, which arrived in 

 perfect health and vigour. He hopes to succeed equally well 

 with exotic mosses, and I see no reason why he should not. 

 Another experiment he has under process, but I fear with small 

 hopes of success, is growing mosses which had long been dried. 

 I don't see why the seeds of mosses should not revive as well as 

 those of ferns ; and should he fail in his attempts at the old 

 stems, he may in this way hope for young ones. 



From Plassey, where William spent the Christmas of this 

 year, he writes thus to Mr. Fennell. 



23 Dec, 1834. 



If thou hast still any pleasure in the " amabilis 



scientia " thou wilt be pleased to get the enclosed specimens of 

 Pinguicula Alpina, one of the loveliest and rarest of British 

 plants. I have just received it from Dr. Hooker. It grew on 

 the mountains of Koss-shire. It is figured in the " Suppl. Eng. 

 Bot." I have this year added a new Potamogeton to the 

 British Flora, P. proelongus. It grows in plenty at Castle- 

 Connell and Plassey. It most resembles small specimens of 

 P. lucidus in appearance. 



Dr. Hooker has presented me with a copy of his " Musci 

 Exotici," a beautiful book, in quarto, with nearly 200 coloured 

 plates. It is a most valuable present. I have just got a parcel 

 of Peruvian plants, among which is a dried specimen of the 

 wild Solanum tuberosum (potato). 



