270 



ACOTYLBDONOUS PLANTS. 



alteration of the original tissues during developement, as well 

 as in the plurality of reproductive bodies, and their inclosure 

 in the finest of all the coats, viz the embryonary sac. The 

 circumcission of the operculum also has its analogies, but the 

 columella is unrepresented. 



In these plants we have three decided points of opposition 

 to the usual Phasnogamous structures, for the Pistillum does 

 not act as a protecting organ to the growing ovulum, or enter 

 into the composition of the fruit, nor does the ovulum enter 

 into that of the seed. Nor has the young reproductive or- 

 gan during the greater part of its growth, any connection 

 but that of contiguity with the parent plant. 



Can they be adduced in favour of the doctrine of compen- 

 sation ? 



If so, then these the most simple of all flowering plants, 

 have the most complex products of fecundation, are the most 

 complex in structure, the most complex in effects, in as 

 much as the embryos derived from each distinct act of fecun- 

 dation, are beyond all comparison indefinite. 



The growth of the seta may without any strained argument 

 be compared with that of the embryonary growth in Rhizo- 

 phora. 



Concluding Observations. 



9. I have elsewhere stated such objections as have pre- 

 sented themselves to me, to which, (and some of them are un- 

 satisfactory) : there is to be opposed the constant access of the 

 moniliform filaments to the interior of the ovulum of Azolla, 

 and the subsequent changes in the foramen and nucleus or 

 basilar protuberances of this organ. Some of the objections 

 might give rise to much speculation. For it can scarcely 

 be doubted that the moniliform filaments of Azolla, could be 

 described as a Confervideae, and would have been taken for 

 one, had the organs of reproduction not been examined. Etc. 

 etc. etc. 



But though obvious difficulties are presented, an explana- 



