fide, fo that the animal can live whether the {kin is turned one
way or the other. The Author of nature did not create the
polype to be turned as we turn a glove; but he formed an animal
whofe vifcera were lodged in the thicknefs o f the {kin, and with
powers to refill the various accidents to which it was unavoidably
expofed by the nature of it’s life ; and the organization neceffary
for this purpofe was fo conftru£ted, that the fkin might be turned,
without deftroying life.
Every portion of a divided polype has, like the vegetable bud,
all the vifcera neceffary to it’s exiftence; it can, therefore, live by
itfelf, and pufh forth a head and tail, when placed end to end
againfl another piece. The vegetation confifts in uniting the portions,
the veffels o f each part increafe in length, and a communication
is foon formed between them, which unites the who'e:
The eafe with which the parts unite, is, as has been obferved before,
probably owing to their gelatinous nature; for we find
many fimilar inftanees in tender fubftances. The folid parts o f
the embryo, as the fingers, unite in the womb; tender fruit and
leaves may be alfo thus united.
A portion o f thefe creatures is capable o f devouring it’s prey
almoft as foon as it is divided from the reft. In the ftructure o f
thofe animals which are moll familiar to us,; a particular place is
appropriated for the developement andpaffage o f the embryo.
But on the body o f an animal, which, like a tree, is covered!
with prolific gems, it is not furprizing that the young ones ftiould
proceed from it’s fides, like branches from a tree. The mother
and her young ones form but one whole; {he nourifties them, and
they contribute to her exiftence, as a tree fupports and is reciprocally
fupported by it’s branches and leaves.
6. Os
O f the H yd ra Pallens.
The hydra pallens has been defcribed only by M. Roefel,
Infec. 3, Polyp. 465, Plate 76, 77; it is very feldom to be met
with, is o f a pale yellow colour, and grows fmaller gradually
from the bottom, the tail is fomewhat round or knobbed, the
arms are about the length o f the body, o f a white colour, and
generally feven in number, apparently compofed o f a chain o f
globules ; it brings forth the young from all parts of it’s body.
Linnaeus defines it as hydra pallens tentaculis fubfenis mediocribus.
Pallas as hydra attenuata corpore flavefcente, furfum attenuato.
O f the Hydra Hyd a tu l a .
The next in order is the hydra hydatula, which we have
already defined from Linnaeus as a hydra with four obfolete arms,
and a veficular body : it is fpoken of by many medical writers,
who are enumerated in the Syftema Naturae, p. 1321. It is
defcribed alfo by Hartman, mifc. nat. cur. dec. I. an. 7, obf. 206,
dec. II. an. 4, obf. 73, as hydatis animata; alfo in the differt.
de inf. viv. p. 50, n. 6, taenia hydatoidea. Pallas defines it as
taenia hydatigena rugis imbricata corpore poftice bulla lymphaticae
terminato. The defcription I {hall give the reader will be ex-
trafled from the Philofophical Tranfaftions, No. 193, by Dr,
Tyfon, who names it lumbricus hydropicus.
In the diffeflion o f a gazella, or antelope, Dr. Tyfon obferved
feveral hydatides, or films, filled with water, about the bignefs o f
a pigeon s egg, and of an oval form, faftened to the omentum, and
fome in the pelvis, between the bladder o f urine and the reftum ;
3 F 2 and