290 ZOOPHYTES. 



it traverses the liquid element in all directions, evidently selecting its 

 course, and occasionally seeking repose of indefinite duration. 



But motion is at length arrested as in the others ; perfect quiescence 

 ensues. By progressive metamorphosis the rudiments of the animal are 

 unfolded as a hydra : then a leaf, as in the Flustra, cells ; or a better 

 shape, with developing tentacula, as in the Actinia. 



Perpetuation of the race by means of gemmules is seen among animals 

 which systematic naturalists separate by wide intervals among the zoo- 

 phytes, such as the Flustra, the Alcyonium, and the Actinia. 



Neither the precise form nor the peculiar properties of the gemmule 

 are yet sufficiently ascertained : nor have I understood that, as elementary 

 stages of the Actinia, though manifesting themselves in the tentacula, 

 they have been detected in the body of the parent. 



An investigation of the disparities to be discovered among gemmules 

 would be very desirable, especially as some seem organised in such a 

 manner as is seldom satisfactorily exposed. 



The original ovum of the larger and more perfect animals at length 

 presents the germ or contents in the advanced stages of the embryo, 

 gradually refined by progressive developement, as the foetus preparing to 

 be ushered into separate existence. 



The young thus generated and matured is contained in a matrix 

 specially designed by nature for its use and protection until reaching 

 maturity. Acute research might perhaps discover some analogous provi- 

 sion in the perpetuation of zoophytes, could observation remount to an 

 early epoch. 



It rather appears that the elements of the young are generally in the 

 lower portion of certain zoophytes, perhaps amidst the polyparium, and 

 that they have a tendency to rise upwards as they advance, and can at last 

 escape when mature. But an organization bearing no imperfect compari- 

 son to a real matrix, is also presented under certain circumstances, con- 

 taining the young, as belonging to the higher products of the creation. 



An ovarium composed of clusters of cysts, is generated externally on 

 the head or hydra of the Tubularia indivisa. Each cyst is a separate in- 

 tegument or capsule, containing an ovoidal, soft ovum, embryo, or foetus. 



