70 ZOOPHYTES. 



obscurity as that in general of the transparent beings which we denomi- 

 nate MedusEe. It will scarcely prove more intelligible if we shall consider 

 them only an intermediate race of animals, like the larva, chrysalis or 

 nymph, among insects, only in the course of transition to some other form 

 or condition, unless we shall actually witness their origin and their end. 



I am not ignorant of the strong disposition of modern naturalists to 

 establish the nearest kindred between the Hydra, comparatively few in 

 number, and the legions of the Medusarian family, thickening the very 

 ocean in their profusion ; but I also know how very prone we are to grasp 

 at every novelty, and our precipitation in adopting as facts what can be 

 offered only as conjecture. 



I say not this to impugn the observations of those ingenious natu- 

 ralists who have proved the truth ; but to restrain the hasty opinions of 

 those who would reason less from facts than from analogies ; and to enforce 

 the expediency of accurate and continued investigation. 



The preceding animals originated and disappeared without leaving 

 any traces behind. Indeed, the smaller medusae never leave any that I 



have seen. 



Another species has sometimes appeared and decayed mysteriously, 

 without affording obvious indications of its origin. — PI. XI. figs. 11, 12. 

 This animal occurs in April ; the former is developed from June until 

 August. It is an eighth of an inch in diameter, with 16 long slender ten- 

 tacular or ciliary organs, disposed in four bundles, which issue from four 

 marginal prominences. At the base of each set is a black speck. The 

 transparence of the medusa is such that while suspended in equilibrium 

 among the water, it is scarcely perceptible. 



I shall be probably enabled to say a few words on the Medusarian 

 race at a future opportunity. 



The evolution of the Medusa ocilia is progressive, accelerated per- 

 haps by external temperature. It has occurred to me under no other con- 

 ditions than as above specified. A number of whitish corpuscula seem to 

 be generated, rather suddenly, among the hydrse, either singly, in pairs, or 

 in clusters of three, four, or five, as already stated. Each is aflBxed by its 

 independent pedicle, and generally about the orifice of a twig of the zoo- 



