HARDWICKE'S SC IEN CE-GOS SIP. 



tenance," like a creditable self-reliant young fellow, 

 who scorns to be a burden on the old folks ; but 

 there are sometimes idle, improvident, shameless 

 young polypes, who do not care to face the world 

 and battle for themselves independently, and who, 

 although they catch everything that comes in their 

 way, still remain on the parent stem, communicating 

 with the paternal canal, " bleeding the governor," 

 no doubt they would say in their slangy way, if they 

 could speak; and not content with thus loafing 

 about at home, they even have the barefaced 

 impudence to start buds and commence families ; so 

 that the poor old gentleman, " Virgregis ipse caper," 

 is made a grandpapa without being consulted, and 

 burdened with the weight of three generations (" as 

 many as nineteen young Hydree have been thus con- 

 nected with a single original stock")]; but although 

 poor old Paterfamilias must find them a heavy drag, 

 and they must try the strength of his hydrorhiza 

 considerably, he has not got to feed them ; each 

 polype is furnished with a set of tentacula and a 

 digestive sac, and fishes for itself. "We regret to 

 say that some most discreditable cases have been 

 recorded, in which highly unbecoming scuffles have 

 taken place for the possession of morsels of food, 

 " nor is it an unusual thing to behold the young one 

 and the old one struggling for and gorging the 

 different ends of the same worm together." This 

 squabbling is the more inexcusable, because it 

 matters not in the end which of them swallows it, 

 for the nutriment extracted from it, in whichever 

 stomach digested, circulates through the intercom- 

 municating canals for the benefit of the whole 

 family, " as appears beyond dispute by the swelling 

 of either when the other is fed." 



Trembley observed the remarkable fact, that the 

 digestive powers of the Hydra had no influence 

 over the tissues of its own body, and he has given 

 an instance of unmannerly greediness on the part of 

 one, that is even more melancholy than that just 

 related : — " On one occasion two Hydra had both 

 seized on the same prey, and were contending for 

 the possession of it ; one of them decided the contest 

 by swallowing the subject of dispute and his rival 

 into the bargain. Naturally supposing that the 

 death of the swallowed polype would be the result 

 of such an apparently tragical termination to the 

 dispute, Trembley was not a little surprised to see 

 the successful polype disgorge his antagonist safe 

 and uninjured along with the egestamenta of the 

 meal, and to all appeai'ance none the worse for its 

 temporary incarceration." 



Sooner or later, however, the progeny are shaken 

 off, and each polype becomes a free and separate 

 individual. This mode of multiplying appears to 

 prevail during the summer months only; there 

 seems to be an analogy between these animal-buds, 

 thrown off in the manner described, and the leaf- 



buds thrown off spontaneously by Bryophyllum 

 calcinum and the bulbiferous lilies, which become 

 perfect separate plants. There is another analogy 

 between these lowly animals and the vegetable 

 world : the Hydra may be propagated like a plant 

 by " cuttings " ; it is even stated by competent 

 observers, who declare that they have themselves 

 ascertained the fact by experiment, that if a Hydra 

 be cut into a dozen pieces, each severed atom will 

 in a short time throw out tentacula, and organize a 

 stomach, and become a polype complete in all its 

 parts, as surely as the " slip " or " cutting " from 

 shrub, plant, or tree will strike root and grow into 

 the "alter ego" of the stem from which it was 

 taken. And there is still another analogy between 

 this humble creature and " the fruit-tree yielding 

 fruit after his kind, whose seed is in itself," for, in 

 addition to the two modes of propagation already 

 mentioned, it is endowed with a third : in the 

 autumn the Hydra generates internal oviform 

 gemmules, which appear as spherical lumps bulging 

 out the skin, much in the form of polype-buds in 

 their first stage. " The ovum here is seen to be sur- 

 rounded by a polygonally-shagreened capsule, the 

 ovum is still enclosed within another capsule 

 furnished to it by the substance of the body-walls, 

 in which, between the endoderm and ectoderm, 

 the generative products are developed." These 

 autumnal ova-buds (or seed-pods) are deciduous, 

 and fall to the bottom of the water, as seeds fall to 

 the earth, there probably to remain unchanged, 

 until the warmth of the welcome spring calls them 

 forth into life. The observation of these ova is so 

 difficult as to be almost impossible : if they have 

 been deposited in the course of nature in a pond, 

 they get out of sight and out of reach, and are lost 

 to us ; if they have been thrown off in a tank, the 

 unnatural conditions to which they are subject are 

 almost sure to prove fatal to them. When this 

 autumn laying is over, and the reproduction of the 

 species has been thereby provided for, the life-task 

 of the humble Hydra seems to have been wrought 

 out ; it has fulfilled its purpose, it has answered the 

 end for which it was designed, and it sinks down 

 and dies. As an organized being, as a Hydra, it 

 dies, and is dead ; yet, strange to say, the substance 

 of which the body was made and fashioned does not 

 die, it is not dissolved into its elements, it retains a 

 life of its own, it exists as a gelatinous amoeba-like 

 living mass, perhaps intended to be used for the 

 building up of some other and widely different 

 animal body. Can it be possible that in this little 

 lump of quivering jelly, lying at the bottom of a 

 glass jar, we have a clue to the origin of that 

 mysterious vitalized matter called Bathyhius, which 

 is said to be spread in infinite quantity over the 

 vast surface of the ocean's bed? This fact con- 

 cerning the body of the deceased Hydra was com- 



