Ghe Scientific Gngniver. 
MAY, 1888. 
Rotifers. 
By J, “Caray EER: 
ROBABLY there are few microscopists who do not expe- 
rience a greater interest in the examination of living 
objects than in that of inanimate ones, and there are few 
objects more readily obtainable than these wonderful 
animalcule. Scarcely any of the leaves or branches of 
our common water-plants can be examined without 
revealing some of these pretty little creatures nestling among 
them, while they are frequently to be found in moss on old walls 
and even in the gutters of houses, where trees are close at hand ; 
indeed, my own supply was, like the excellent old Leuwenhoek’s 
(who first directed attention to Rotifers), derived from the latter 
source. 
The Rotifera form a most interesting study, so let us glance at 
their organisation. There are several kinds, varying materially in 
size and shape, the males being more perfectly organised than the 
females. 
If we place some of these wonderful creatures in a live cage, 
and examine them with the inch power of our microscope, we 
shall get a better idea of their structure and habits. The first 
things we notice when we get our glass into focus are some little 
yellowish bodies, of an irregular oval shape. Watching one of 
these, we presently observe a slow bulging at one end and then at 
the other. The oval suddenly elongates itself into a form not 
unlike a caterpillar, except that there is a tapering at one end. 
Now a forked tail becomes visible. This fixes on to the glass, 
while the body sways to and fro. Presently the head is drawn in, 
as if it were swallowed, and suddenly in its place are unfolded 
two broad membranes, having each a circle of waving cilia, which 
bear a very striking resemblance to wheels, and which appear to 
revolve with great rapidity, while at the same time the jaws 
Vou. III. 5 
