154 
Popular science review. 
“The free Vorticella, that is, the calyx which has been 
detached, swims about very rapidly by means of its two circlets 
of cilia; but at length one of these disappears, namely, the 
circlet that was originally situated at the rim. This end of the 
calyx then attaches itself to some floating object, and puts 
forth a pedicle or footstalk, the opposite end becoming the one 
at which food is received, for a new e mouth ’ is formed within 
the wreath of cilia that aided to twist it off the old footstalk. 
So you see the parts of the calyx change their functions, and 
very soon the process of subdivision commences afresh. 
“ Sometimes, however, the fission is not confined to the 
calyx, but extends into the pedicle ; and under these circum- 
stances, it is incomplete, and the two animalcules, or rather the 
two cups, remain permanently attached. When this abnormal 
process is often repeated, the whole group assumes an arbo- 
rescent appearance, and such a group has obtained the name of 
Carchesium, or the Tree- Vorticella (pi. viii., fig. 6).* The group 
of living flowers, therefore (in some cases attached by then- 
several footstalks to one central stem), is the result of one of the 
reproductive processes in Vorticella, namely, that of fission or 
subdivision. 
“ The next is called ' gemmation’ or ‘ budding / but it is 
not of such frequent occurrence Let me 
endeavour to illustrate this budding- process by a simile. Can 
you imagine a Canterbury-bell producing another cup through 
the growth of a bud, not upon the footstalk, but close to it, on 
the flower itself? If so, you will understand how the young- 
Vorticella-bud grows, as it were, from the calyx of the parent 
(pi. viii., fig. 3). It is nourished by a connection with the latter 
until old enough to lead an independent existence, and then a 
circlet of ciha is developed at the part attached to the parent, 
by which means, as in the former case, it frees itself, swims 
about with the aid of its cilia, develops a pedicle, and becomes 
sedentary, or f sessile/ as it is scientifically called.” 
“ Just as in our case,” said my pupil, laughing ; “ first it 
leaves its parents to sow its wild oats, and then settles down to 
a quiet life.” 
“ Precisely so : and now for the last process of multiplication, 
which is rather more difficult to describe in popular language 
than the others, but I will do my best to explain it. 
“Within the cup of the Vorticella there is a little sausage- 
shaped object called the ‘ nucleus.’ (PI. viii., fig. d.) At a 
certain stage of its humble existence the animalcule shrinks up 
into a ball, and a gelatinous or glutinous substance exudes 
from its body, entirely encasing- it. In this state it is called 
* From Dujardin’s “ Zoophytes Infusoires.” 
