94 ZOOPHYTES. 



Aulopora and strawberry-creepers, before the final developement of 

 the complete individual. This budding of cellules, moreover", is 

 closely analogous to the budding of polyps and branches in the 

 zoophyte. 



92. The ovarian vesicles, which pullulate from the sides of a 

 branching Sertularia ( 14), contain the ovules arranged on the same 

 general plan as the polyps of a branch formed by the process of 

 budding, though much contracted. They communicate internally 

 with an axis, branching from the trunk of the zoophyte, just as the 

 several polyps of a branchlet communicate internally with its tubular 

 axis. There is the same condition of things in this case as in the 

 last-mentioned, the same process of branch developement : and all 

 cases of the production of numerous ova in animals, appear to be 

 analogous. The fact, that the kind of ramification is similar to that 

 of the zoophyte, as a whole, is not peculiar ; for the same is true of 

 the lilac thyrse : and generally among plants, the mode of branching 

 in the flower clump, is but a miniature representation of that which 

 characterizes the whole plant.* 



* Professor E. Forbes has drawn a comparison between the vesicle of a Sertularia 

 and a flower, in which he compares each ovule of the vesicle to the carpels or parts gene- 

 rally of the flower-bud ( 14). The analogy, as exhibited by this distinguished physio- 

 logist, is highly interesting, and was the result of much minute research. But, while 

 admitting the correctness of the analogy, in a certain light, we may doubt if the compa- 

 rison gives us a correct idea of the actual nature of these vesicles. In the Actinia, with 

 its circle of tentacles, and its inner series of ovaries and spermatic organs, we appear 

 to have the true analogue of the flower, as perfect as can be presented by animal life. 

 And in the vesicle of the Sertularia, we see the analogue simply of one of the clusters 

 of ovules in an Actinia. These clusters project into the interior cavity in the Actinia, 

 as the animal has ovarian lamella: there, but become external in the Sertulnria ; in other 

 respects, the cases are wholly identical. It is, therefore, more in accordance with the 

 developements in other zoophytes, to consider the vesicle as the analogue of a cluster of 

 flower-buds ; and we may, with much justice, compare it to the branching clump of 

 flowers proceeding from a single budding-point, the axil of a single leaf. Professor 

 Forbes's comparison holds only on the ground of the general analogy which subsists 

 between all reproductions ; the same principle presiding over the origin of a flower, or 

 a leaf, or the cellules that give origin to the leaf. The cluster of seed attached to a pla- 

 centa, of ovules to an ovarian lamella, the external vesicle of a Sertularia, and a compound 

 flower-bud, are therefore proper analogues. 



The observations afford exemplifications of the fact, that each ovule is connected in 

 origin with the production of a certain part of the general ovarian envelope ; and this is 

 as true of the internal clusters of an Actinia, as the external of a Sertularia. In the 

 latter, the fact becomes apparent, through the horny secretions of the exterior, which 

 conform to certain principles, exhibited in the production of a calicle. 



