THE CROWN ANIMALCULE. 
39 
his observations for the most part, and have also extended 
them. I shall speak of what I have seen, except where my 
experience differs from his. 
Between the most matured egg in the ovary and the cloacal 
orifice, lies the oviduct, a membranous tube of great expansi- 
bility, but when not in use longitudinally corrugated so as to 
occupy a very slender space. When quite ready, the egg is 
rapidly forced through the oviduct, and in a moment escapes 
through the protruded cloaca into the interstice between the 
body of the parent and the wall of the enveloping case, the 
gelatinous substance of which yields to the pressure of the in- 
truding egg. Here it lies close to the cloacal orifice for a short 
time, varying from half an hour to several hours, at the end of 
which the young is hatched (plate iii. g). In one instance 
which I watched from the discharge of the egg to the hatching, 
the escape from the shell took up several minutes, and appeared 
a laborious task, reminding me of a caterpillar becoming a 
chrysalis. In general the liberated young slowly presses its 
way upward between the parent and its case, till it emerges at 
the margin ; but the one that I have just mentioned made its 
way through the side of the case near the top, boring, as it 
were, a passage through the gelatinous substance by means of 
its vibrating cilia; the force of the ciliary currents apparently 
abrading the soft jelly atom by atom. Dr. Mantell mentions 
one which penetrated through the bottom of the case, a process 
which occupied three hours before it obtained freedom. 
As soon as the young is free from the parental case, it swims 
vigorously away. Its length is now about one hundredth of an 
inch, or nearly one-sixth that of the adult (plate iii. h). Its 
form bears a rude resemblance to that of the parent, except 
that there is no trace of the coronal arms. The front is rounded, 
well set with strong vibratile cilia ; the body is cylindrical, with 
many transverse corrugations, and a short thick foot is distinctly 
marked. The interior is occupied by a granular, often turbid, 
gelatinous flesh ( sarcode ), in which are placed many irregular 
bubbles (perhaps oil-bubbles), a few large bladder-hke organs 
(the rudiments of the future viscera), traces of the five muscular 
bands, which subsequently will move the arms, the jaws, well 
formed and situate near the middle of the body, two brilliant 
red eyes near the front, and the opaque white urinary mass 
near the site of the cloaca. 
Having swum giddily about for a while, — longer or shorter, 
from a few minutes to half an hour, — it becomes stationary, 
finding a resting-place for its foot. In the live-box of the 
microscope it generally affixes itself to one of the glass surfaces. 
The specimen which I have before mentioned, winch was 
hatched under my eye, swam for ten minutes, and then became 
