GEMMATION OF RADIATA AND ARTICULATA. 555 
are in reality the representatives of the flower-buds of Plants, 
istinguished by their capability, not only of living and en- 
during, but of obtaining their own nu- 
triment, after their spontaneous detach- 
‘ment from the stock that bore them. 
Among the Meduse we occasionally 
meet with instances of propagation 
| by buds that resemble the stock from 
which they proceed, and that are 
thrown off in due time so as to lead 
independent lives; but this kind of 
emmation seems limited to ihe lower 
members of the group. In a large 
proportion of it, however, avery extra- 
rdinary kind of multiplication b : 
gemmation takes place at an ouiy oe i iigaes is 
period of development ($ 740).—In Undergoing fission; a, b, ¢, 
the highest Radiata, ne pte We reer 
Echinodermata, we take leave of multiplication by gemmation 
together ; for although the bodies of these creatures possess 
very extraordinary reproductive power, so that the result of 
yery severe injuries may be repaired (§ 389), we do not find 
that they either spontaneously produce independent buds, or 
that they have the capacity for being multiplied by artificial 
livision. 
727. Among several of the lower Articulata, detached 
{Segments of the body appear to be capable of reproducing the 
whole ; and there are some whose ordinary propagation is 
=~ 
She. 
y) sit Atteguce 
oy 
a 
es 
Fig. 298.—Nerreis Pro.irera. 
accomplished by an exercise of this power. Thus in the Vais, 
im aquatic worm allied to the Earth-worm, the last joint of the 
sphody gradually extends and increases to the size of the rest of 
whe animal ; and a separation is made by a narrowing of the 
