408 Original Articles. [July> 



place upon the nutritive energies in their behalf, as we have seen it in 

 Coryne. In other cases, both mouth and arms are suppressed, and the 

 reproductive bodies bud from the sides of a simple off-shoot from the 

 common trunk. This condition obtains almost universally amongst the 

 Campanularian and Sertularian Zoophytes, and in these tribes the fruit- 

 bearing shoot traverses the centre of a horny capsule, which envelopes 

 and protects the whole brood of sexual zooids, as the ordinary calycle 

 shelters the polypite. In Plate ii. fig. 9, we have a representation of the 

 reproductive capsule of a Campanularian Hydroid (Laomedea amphora, 

 Agassiz). The horny envelope (a a) is supported on a short ringed 

 pedicle (b), by which it is attached to the Zoophyte at the base of the 

 longer stalks, which bear the cells of the polypites (Hydro-thecce). 

 From one extremity of the capsule to the other passes the off-shoot 

 (c c) from the common pulp, on which the reproductive buds or zooids 

 are borne (d). This shoot is plainly a Hydra, arrested in its develop- 

 ment before the formation of a mouth and tentacles, and dependent for 

 food on the supplies which are brought to it by the general nutritive 

 stream, which circulates, like the water through a town, to every part of 

 the colony, and which enters it through an orifice at the base. It 

 would appear, in some cases, to declare its essential nature by deve- 

 loping the missing parts and assuming the perfect polypite form, 

 when the reproductive bodies have run their course and discharged 

 their contents. Ellis at least figures Hydrae protruding from the cap- 

 sules of Sertularia pumila, and we have had no more trustworthy ob- 

 server. For this imperfect polypite, whether naked, as in the Hydrac- 

 tinia (Plate i. fig. 5), or enclosed, as in the case before us, a special 

 name has been invented, and in conformity with the present unhappy 

 fashion, it is a Greek compound of six syllables — Gonoblastidium, or in 

 a mitigated form, Blastostyle ! We venture to protest against this in- 

 fliction, as both unnecessary and in some degree deceptive. The 

 mouthful of Greek, which may well set the teeth of the young or un- 

 learned naturalist on edge, is more likely to divert attention from the 

 real significance of the body in question than to help the student to 

 interpret it aright. Who would venture to recognize a familiar friend 

 in a Gonoblastidium ? In fact, it is a fertile polypite — a Hydra which 

 bears the sexual buds, and is somewhat enfeebled by the work,— and 

 why, in the name of common sense, should this intelligible designation 

 be translated into Greek or any other learned language ? 



The reproductive buds are also developed, in some species, on the 

 stem and branches, and rarely on the creeping stolon, which origin- 

 ates and unites the several shoots that compose the Zoophyte. 



And now a word as to the nature of the buds themselves. In the 

 first place, they are male and female — one set giving rise to the ova, 

 and another to the spermatozoa. Sometimes the two sexes are borne 

 on the same colony ; sometimes, and more commonly, the male and 

 female zooids occur on separate colonies. The Zoophyte, like the 

 plant, is dioecious or monoecious ; and the latter condition is of more 

 frequent occurrence than has been supposed. Professor Allman gives 

 one or two instances of it as strictly exceptional, but we have met 



