CULTIVATION. 



397 



are formed on its under surface, of two kinds, one 

 called Antheridia, and the other Archegonia ; the first 

 (of which there are generally between 30 and 40) con- 

 taining round cells, called sperm cells, which contain 

 vermicular spermatozoids that issue from the cells 

 when arrived at maturity. The cells of the Archegonia 

 differ considerably in their structure from the Anthe- 

 ridia; they contain an embryonal sac, which at a certain 

 period protrudes from the cell, and with which the 

 moving spermatozoids are said to come in contact, and 

 thus produce fertilization ; soon after this the embryo 

 sac is changed, a bud is formed, and ultimately a young 

 Fern Plant is gradually developed, and in time the 

 Prothallium decays. This singular phenomenon excited 

 considerable interest, and has been carefully inves- 

 tigated by the late Professor Henfrey and other 

 eminent microscopists.* 



Although the above is only an outline of the prin- 

 cipal points of this curious subject, yet it \vill be suffi- 

 cient to draw the attention of Fern seed sowers to the 

 subject, and materially assist them in understand- 

 ing, and arriving at the cause of the many anomalies 

 in the good and ill success attending the raising of 

 Ferns from seed. Much has, however, yet to be 

 investigated before any rule can be arrived at ; such as 

 why ikeDesmobrya division does, as a general rule, pro- 

 duce plants from seed in the greatest abundance, even 

 to some species becoming the weeds of the hothouse ;, 

 while, on the other hand, those of the division Eremo-. 

 brya are comparatively few, and may be considered, 

 the exception and barrenness of this rule. The differ- 



* Henfrey, in Lmncean Transactions, vol. xxi. 1853. 



