HYDRA. 93 



its side, had removed to some distance, fig. 23, a ; and while this young 

 hydra, a, was advancing, another, b, had also withdravra. Meantime, a 

 new bud germinated from the parent, c, then entire, which continued to 

 propagate. — Fig. 24. 



Thus the upper portion, sundered from the specimen Plate XIV. 

 fig. 15, may he traced through figs. 18 (enlarged, 19), 20, 21, 22, 23, 24. 

 The first, fig. 18, representing that mutilated fragment : the last, fig. 24, 

 representing the same fragment 150 days later, completely redintegrated, 

 and generating a new colony. 



As the stumps, or under halves of fig. 1, «, of fig. 3, a, and of fig. 3, Ij, 

 which had all three suffered bisection, by removing the upper part, re- 

 mained adhering, I say, as all three subsequently regained tentacula, and 

 became the parents of future progeny, the reproductive faculties residing 

 in them, not only for the restoration of lost parts, but for perpetuating 

 their race, were not extirpated by such an excessive mutilation. 



It may be remarked here, besides, that both the sections of the same 

 sundered animal having generated progeny, demonstrates one of two facts, 

 — either that all the embryonic elements are not concentrated in a single 

 point, which would restrict their evolution as hydra; to one of the sections 

 only ; or that the elements of the progeny are secreted and deposited pos- 

 terior to mutilation, to be evolved by gemmation at a suitable period. 



No important injury had, therefore, followed bisection ; for both 

 portions grew, and fed and bred in the same manner as entire animals. 



The preceding narrative proves, /^-aV, That redintegration of the organs 

 defective in the Hydra tuba, follows precisely as after mutilation of those 

 species of the hydra proper dwelling in the fresh-waters of Scotland. 

 Second, That the elements of the progeny, whether in a primordial germ, 

 or secreted and deposited from the parent, are neither restricted to a single 

 point nor to one half of the body. Third, That both the stump below, and 

 the section above, becoming entire animals, alike complete, by the evolu- 

 tion of new organs, and the preservation or acquisition of the faculties 

 essential for the living creatures, the name and character of hydra had 

 not been misapplied. 



I speak of general results and appearances, for in a long course of 



