268 MR MACVICAR on the Germination of the Filices. 



cotyledon, a plumule and radicle, and of germinating in a de- 

 terminate manner, and from a single point ; they are composed 

 of a mass, whose internal structure is uniform, and on the sur- 

 face of which frequently more than one germinating point are 

 visible. And, there is reason to believe, that there are other 

 families in this class, the structure of whose seeds is equally ano- 

 malous. 



The author of the article alluded to was led to conclude, 

 from his observations, that the seed-lobes of ferns possess not 

 only an analogy with, but partake of the essential properties of 

 cotyledons, as far as these have been accurately denned ; and 

 though he mentions some respects in which the germination of 

 ferns is peculiar to this family, he gives particularly three in 

 which it agrees with other dicotyledonous plants. The first is, 

 that the seed-lobes constitute the body of the minute seed. 

 Should the general mode of germinating throughout the family 

 be uniform, of which, as that writer remarks, there can be little 

 doubt, this cannot be the case ; for in every instance where the 

 sporule has been seen, and as long as it has been observed, it re- 

 mained of nearly its original form and size, which could not have 

 happened, had not what have been considered as seed-lobes been 

 solely the result of germination. The other two are, that these 

 seed-lobes nourish the other organs of the embryo, which they 

 include within their substance ; and that these organs germinate 

 from a tuber situate in the centre of the lobes. They certainly 

 do nourish the true bud, after they have disposed of the nutri- 

 tious matter derived from the radicles for their own aggrandise- 

 ment, until the law of their life does not permit them to increase 

 in size, but not till then do they form a bud ; and their action in 

 doing so, is not by yielding any albuminous matter contained in 

 their substance, as in true cotyledons, for they are thin cellular 

 membranes, and their function seems to be to convert the fluids 

 received from the numerous radicles on their under surface, into 

 the forms of the species. 



