58 ZOOPHYTES. 



ral cavity of the same is usually prolonged : developement goes on, 

 and shortly a mouth and a circlet of tentacles appear at the extre- 

 mity. In some cases, the visceral cavity of the young continues 

 afterward to open into that of the parent ; yet, generally, the com- 

 munication gradually closes as the young grows, leaving usually an 

 imperfect cellular connexion. 



In other instances, especially when the buds appear outside of the 

 disks (a variety of terminal budding), there is not at any time a con- 

 nexion with the visceral cavity of the parent, except through the 

 intermediate lateral pores or lacunal spaces. 



In disk-budding, a new mouth opens in the disk, without any pre- 

 vious external indication of the changes in progress; and, as the disk 

 is situated over the visceral cavity, the new polyp for awhile, at least, 

 shares with the parent in this cavity : in many instances, the two 

 animals subsequently become separate by a process of growth, here- 

 after to be described (H 77, 79). There is no satisfactory evidence, 

 as yet, that the budding polyp divides the stomach of the parent as 

 well as the visceral cavity. 



The budding process goes on without any necessary connexion 

 with coral secretions. These secretions, however, are usually in 

 progress at the same time within. 



The buds, both inferior and superior, in many instances, become 

 nearly adult polyps, before they give out other buds. Very fre- 

 quently, however, a budding shoot continues lengthening uninter- 

 ruptedly, like the creeper of a plant, and gives out buds at intervals. 

 These shoots are called stolons or creepers by Ehrenberg, who first 

 laid down the distinction among zoophytes. Broad plates of polyps, 

 and the margins of many massive species, increase in this manner, by 

 a gradual extension outward, and an accompanying production of buds. 



54. Milne Edwards has shown, that the lateral buds in an Alcy- 

 onium are developed from one of the visceral lamellse the same 

 parts that produce ovules. He found that the new visceral cavity, 

 where it opened into that of the parent, intersected a lamella, and 

 that this bisected lamella was deflected into the cavity of the young 

 polyp. It would hence seem, as Edwards suggests, that the bud is 

 the developement of a germ or germinating cellule laterally through 

 the sides of an animal, instead of its maturing within and escaping 

 through the mouth. This indeed should be inferred from the nature 

 of germination. The general result is the same, whether a cellule 

 developes an ovule, or a bud ; for it is an animal with like powers and 



