ACALEPELE. 
209 
Wanderer, twining its flexible arms round it, and, directing it rapidly 
Wards its month, swallows it. Trembley amused bimselt by feeding 
tbe Hydra, while he observed the manner in which it devoured its prey. 
“ When its arms were extended, I have put into the water a wood- 
louse or a small worm. As soon as the woodlouse feels itself a prisoner 
d struggles violently, swimming about, and drawing the arm which 
holds it from side to side ; but, however delicate it may appear, the 
ari n of the polype is capable of considerable resistance; it is now 
gradually drawn in, and other arms come to its assistance, while the 
Polype itself approaches its prey ; presently the woodlouse finds itself 
Gn gaged with all the arms, which, by curving and contracting, 
gradually but inevitably approach the mouth, in which it is soon 
en -gulfed.” Fredol also notices a singular fact. “ The small w’orrns. 
ev en when swallowed by the polype,” he says, “frequently try to 
oscape ; but the ravisher retains them by plunging one of its arms 
1J ito the digestive cavity ! What an admirable contrivance, by which 
Hie worms are digested while the arm is respected !” 
fhe food of the fresh- water Hydra influences the colour of their 
odies in consequence of the thinness and transparency of their 
issues ; so that the reddish matter of the woodlouse renders them 
'' e 'l, while other food renders them black or green, according to its 
prevailing colour ! 
Tire multiplication of these creature.? takes place in three different 
^ a ys: 1. 13 y eggs. 2. By buds, after the manner of vegetables. 
J ' Ty separation, in which an individual may he cut into two or many 
Se gments, each reproducing an individual. 
We shall only say a few words on the first mode of reproduction. 
ie eggs j according to Ehrenberg, come to maturity in the II. Hindis 
a ! the base of the feet, where the visceral cavity terminates. They 
are 
carried during seven or eight days, and determine by their fall the 
cath of the an ] ma i_ When the Hydra has laid its eggs, according to 
. • Laurent, it gradually lowers itself until it covers them with half 
1 S l’ 0( ly, which, spreading out and getting proportionably thin, passes 
fhe condition of a homy substance, that glues the eggs disposed in 
circle round the body to plants and other foreign substances. She 
6llc ^ her career by dying in the midst of her ova. 
Trembley has studied with great care the mode of reproduction by 
wlirig — a process which seems to prevail in the summer months. 
