1-22 ZOOPHYTES. 



The condition of a forming bud, that is, the nutrition present and forces at work, seem 

 to render it liable to this abnormal developement in animals of the lower grades, in which 

 the formation of an ovule is little more than the reproduction of any other cellule in the 

 body. The ovigerous portion of any animal must be that best fitted in these respects for 

 the developements required ; and in these inferior organizations, the powers of reproduc- 

 tion are more generally distributed, as less concentration is needed. 



Van Beneden has observed, that in the Corynse and Hydractinioe the stomachs of the 

 several polyps in a compound zoophyte are isolated, instead of communicating with one 

 another along an axial tubular cavity ; and that consequently there is no circulation in 

 these animals like that of other Hydroidea. This fact decides the unimportance of the 

 character upon which the Alcyonaria have been hitherto so widely separated from the 

 Actinaria. See note to page 45. 



Reproduction in the Alci/nnaria. — p. 43. 



Milne Edwards, by his dissections of the Veretillum cynomorium^ illustrated by excel- 

 lent figures in the late edition of Cuvier's Regne Animal (Paris, 1837, pi. 91, fig. 1), shows 

 that both spermatic cords and ovarian clusters sometimes occur attached to the same 

 lamellse. The figures represent the upper part of the lamellre as spermatic and the 

 lower part ovarian. It is interesting to observe the close analogy here exhibited to a 

 gynandrous plant. Two of the lamellae, however, as in the Tubipora described in the 

 text, were without spermatic cords. 



Structure of Coralla. — p. 51. 



Under a microscope of moderate power, animal fibres may be readily detected in a 

 thin slice of coral, ramifying irregularly throughout it. But beyond this, even with an 

 instrument magnifying three hundred diameters, I have been unable to discover any re- 

 gular structure that can be traced with certainty to the pre-existence of separate animal 

 cellules. In the lamellee of the Euphyllia gracilis and Astrsea dipsacea, polished down 

 and examined with the power above specified, only a minutely clouded appearance was 

 made out, too indefinite in character to be represented. By rubbing a crayon over a 

 piece of paper a little rough, as good a figure of it would be had, as a more laboured 

 sketch could give. There were parallel bands of light and shade corresponding in direc- 

 tion with the margin of the plate, and with all its dentations, which indicated what other 

 observations had shown, that these plates gradually enlarge by the extension of the 

 edge; and this was the only evidence made out of regularity of structure. Examined 

 with a polarising attachment to the microscope, the thin slices permitted the polarised 

 light to pass, but no colours were exhibited, except in points which were extremely 

 minute when magnified one hundred and fifty diameters, the power used in making the 

 observation. This fact indicated that the coral plates were composed of minute granules, 

 confusedly aggregated, as if each had been the result of independent formation, or the 

 secretion of a separate animal cellule. There was no reason whatever to infer that the 

 particles of the plate had been secreted and accumulated by superposition under crys- 



