556 SUPPLEMENT 
The mode in which the intercourse of generation takes 
place, is but little known. M. Bremser has observed it in the 
strongyli. The pouch or sac of the male embraces the vulva 
of the female. 
The result of generation after this intercourse, or even when 
no intercourse takes place, as is the case with all the monoga- 
mous species, is, as we have already said above, often innu- 
merable eggs, as in the tenie, for example. These eggs do 
not adhere to the mother. They are formed in the meshes of 
the cellular tissue which constitute the ovary, and are rejected 
through a determinate orifice, in most cases, or through’ a 
simple rupture, as in the teniz. 
Be this, however, as it may, they fall into the substance in 
which they are to be developed, without receiving any parti- 
cular arrangement or disposition from the mother; with the 
hirudines, which we have so often said are very analogous 
animals, if, indeed, they ought not to be placed in the same 
class, the case is different. Their eggs are united in small 
packets, by a general mucous envelope, and are arranged by 
the mother in determined circumstances. Such appears never 
to be the case with the entozoa. 
We know nothing, or scarcely any thing respecting the 
mode in which their eggs are developed. M. Rudolphi thinks 
that their development is rapid. Nevertheless, it appears, 
that in the bothryocephalus, so common in the pleuronectes 
maximus, the young subjects bear no resemblance to the 
mother. They at first exhibit no trace of articulation. The 
cephalic enlargement constitutes almost alone the whole of 
the body of the animal, which is terminated rather abruptly, 
by a small caudiform elongation. In the next degree of deve- 
lopment, the body increases in size. The articulations be- 
come sensible by simple lateral denticulations. They are as 
yet few in number and very long. By degrees they cut and 
wrinkle, and other articulations become defined. ‘This cir- 
