488 
POPULAR SCIENCE REVIEW. 
vigorously ; a little opaque body, white under sunlight, was in 
the posterior part. This embryo died without being hatched. 
I found a young one, about half-adult size, attached by the 
base of its tube to the side of the tube of an adult, near the 
summit of the latter, so as to project obliquely upward. This 
specimen, which was perfectly formed, gave me an excellent 
opportunity for observing the ventral aspect and the dorsal. It 
had two red eyes, one placed near the base of each larger petal. 
I have never discerned the eyes in adults. It was very ener- 
getic, diligently engaged in manufacturing the pellets and lay- 
ing them on. It seems that the action of the pellet-cup is 
voluntary, and not always coexistent with the passing of the 
ciliary current over the chin. The animal frequently makes 
abortive efforts to deposit a pellet, and sometimes bends forci- 
bly forward to the edge of the case before the pellet is half 
formed. 
This specimen lived with me fourteen days after I dis- 
covered it, active and apparently healthy, till it suddenly died. 
During the whole time it scarcely increased in size, nor did it 
add any pellets to its case, except a few in the first day or two. 
The eyes remained distinctly visible to the last. It would be 
interesting to know the natural period of life in these little 
creatures. 
On another occasion, looking into the animalcule-cage, in 
which were several cases, I found a young one swimming 
rapidly out in a giddy, headlong manner. I believe it was just 
hatched. Its form was somewhat trumpet-shaped, or like that 
of a Stentor, with a "wreath of cilia around the head, interrupted 
at two opposite points. The central portion of the head rose 
into a low cone. After whix-ling about for a few minutes, its 
motion became retarded, and it began to adhere momentarily, 
and to move forward by successive jerks, not more than its own 
length at once. The period of its remaining stationary in- 
creased, so that I several times supposed it had taken perma- 
nent position, when some shock or alarm would send it off for 
a little distance again. At length, about an horn* after I first 
saw it, it finally settled, adhering by the foot to the lower glass 
of the box. After a few rapid gyrations upon the foot as a 
pivot, it became vertical. The form of the adult was now dis- 
tinctly assumed ; the four petals of the disk were well made out, 
though the sinuosities were } r et shallow : the antennae at first 
were only small square nipples, but soon shot out into the usual 
form ; the ciliated chin was distinct, as was also the whirling 
of the pellet-cup immediately beneath it. A pellet was quickly 
formed, and instantly deposited at the foot — the first brick of 
its house ; the same operation was repeated xvith energy and 
