543 



M ARSILE ACE.E. 



I know of no parallel instances to the lobes surmounting 

 the yellow sac in Azolla, and especially the tissue, which on 

 being pulled separates in the form of radicels. There are 

 reason, as I have stated, for supposing the lobes themselves 

 to be modifications of the spores* and comparing the early 

 number of nuclei or points of condensation with the mature 

 number of the lobes, the opinion becomes suggested, that 

 these receive their developments at the expense of others* 

 However this may be, their analogy with the solid masses of 

 the spherical pedicellate secondary capsules appears suffi- 

 ciently obvious. They are not in any way to be referred to 

 the incrustation, which does not, I think, become organished ; 

 and which moreover, appears somehow or other connected in 

 every instance with the difformity of the organs. 



In conclusion it appears to me sufficiently plain, that in 

 the higher Acotyledonous plants, in which I include Filices, 

 Lycopodineae, Isoeteae, Equisetese, Marsileaceae, Salvinidae, 

 Musci, Hepaticae, Characeae, there are at least two modifica- 

 tions of the female organ representing the modifications of 

 the same organ of Cotyledonous plants. 



The term Pistillum has been applied to the female organ 

 of Mosses by some first-rate Botanists, though not without 

 violent opposition from others. Since the examination of 

 Balanophora, its application is, if possible, still more legi- 

 timate. In my opinion it is not to be doubted, that not 

 only have Musci and Hepaticse a pistillum, but that this con- 

 tains an ovulum.* 



The analogies presented by the plants which form the sub- 

 ject of this communication, to those Cotyledonous plants in 

 which the ovulum is entirely naked, either, as is supposed to 

 be the case in some, without a carpel leaf, or with that organ 

 in an expanded not a convolute state, are I think equally 

 striking, 



* See also Mr. Valentine, Linn. Trans, xvii, p. 466, 67, t. 23, f. '1 

 2, 6 ; where it is stated, that the development of the capsule depends on 

 the presence of the cell (or ovulum) in the pistillum. 



