HISTORY OF THE ROTIFERA, OR WHEEL ANIMALCULES. 495 
individual life of the stock ; but that produced from a seed is a 
new plants a new generation. 
Experience shows that this, like the former species, cannot 
long survive confinement. I have already mentioned the fate 
of M. volvox in my possession ; Ehrenberg says of socicdis : 
“ In vessels of water they rarely support themselves eight days ; 
they die and fall to the bottom, even if plants be growing in 
them.” 
EXPLANATION OF THE ILLUSTRATIONS. 
Plate X. represents a shoot of Nitella with stationary Melicertadce adhering' 
to it, and a free cluster of Megalotrocha. 
Fig. a. Melicerta ringens, viewed from behind. 
b. The same, viewed from the side. 
c. Melicerta ceratophylli, viewed from behind ; with two eggs in its case, 
attached to the foot. 
d. Melicerta ptygura (?) viewed from the side. 
e. A large cluster of Megalotrocha volvox, freely rotating and swimming. 
Some are viewed vertically, some from the front, some from the side, 
and a few are closed. 
/. Eggs of the same, held in the ciliary vortex, and seen in various 
positions. 
The whole magnified about 350 diameters. All the figures taken from 
the life. 
