104 AZOLLA. [BOOK i. 



calyptra ; on the surface of the fibrous tissue are nine cellular 

 lobes (the three upper the largest), which, when pulled away, 

 separate with some of the fibrous tissue, and so appear pro- 

 vided with radicles. The globose capsule has a rugose surface 

 from the pressure of the secondary capsules within ; these are 

 many in number, spherical, attached by long capilliform pedi- 

 cels to a central much branched receptacle ; each contains two 

 or three cellular masses, presenting on their contiguous faces 

 two or three radiciform prolongations. In their substance 

 may be seen imbedded numerous yellow grains, the spores. 



I profess myself unable to understand in what respects 

 the parts here called males, females, ovules, capsules, &c. 

 resemble those organs except in name. Indeed Mr. Griffith 

 himself could not help feeling the weakness of his case when 

 he observed that, " A difficulty may be considered to be pre- 

 sented by the existence of the hairs round the base of the 

 ovula. For these in their structure resemble what I suppose 

 to be the male organs of Ferns, and also the anthers of 

 certain Mosses and Hepaticse; although the terminal cell 

 presents less granular matter than usual. In respect of 

 the supposed males, Azolla presents greater analogies with 

 phanerogamous plants, than either Musci or Hepaticse, in 

 which nothing analogous to pollen grains has been, I believe, 

 yet observed in the anther ; which again can scarcely in all 

 cases be considered a grain of pollen, the view suggested by 

 the contents. Still even with the objections before mentioned 

 the analogies are as tenable, I think, as those existing between 

 the pistilla of Mosses and of phanerogamous plants; those 

 organs in the former being originally closed, in the latter, 

 theoretically at least, originally open. General objections 

 may also be raised from the fact of moniliform filaments 

 similar to those of Azolla having been found on the capsule 

 of Salvinia, unconnected apparently with fecundation, and on 

 the dissimilarity of the supposed fecundating process in the 

 two genera." Opinions in which I quite concur, regarding 

 them indeed as being fatal to a sexual theory in this case. 



It has been thought that of the two kinds of grains or 

 bodies above mentioned, the smaller are males and the larger 

 females ; which has been supposed to be proved by the 



