Short Papers and Notes. 127 
The embryo, if sufficiently large for sectionising, is hardened in 
picric acid (Kleinenberg’s formula). A three days’ embryo cannot 
be thus dealt with, but should be treated with a 1 per cent. solution 
of osmic acid. Ina few minutes the preparation is sufficiently 
dry to cause adhesion to the cover. This readily permits the 
examination of the embryo, which is protected from drying by the 
amniotic membrane and its contained fluid, and its outline is thus 
clearly distinguishable. The next stage is immersion in Miiller’s fluid 
for 24 hours, which prevents curling when afterwards transferred 
to Kleinenberg’s fluid to harden. ‘The final stages are treatment 
with alcohol of various degrees of strength to remove water, 
clearing with oil of cloves, which removes the alcohol, and the 
preparation is finally mounted in Canada balsam.—Leeds Mercury. 
Frail Animal Lite. 
One summer day I took a few eggs of the common “ horn- 
pout,” or “cat-fish” (P. atrarius), from under a board in the creek 
and put them ina small dish of water. They had probably just 
been deposited there, as there was a fish with them. Each egg 
consisted of a small yellow part, surrounded by a semi-transparent 
part of a whitish colour ; in a short time a small white spot made 
its appearance in the centre of the yellow part. It grew larger 
and soon two eyes began to develop in the white spot, and later a 
small stream of blood began to pass from the lower part, upward, 
toward the eyes, and passing, drop by drop, disappeared under the 
now large, head-shaped portion that contained the eyes. This 
white part, gradually assuming a darker colour, began to protrude 
and shape itself more and more until it extended some distance 
from the yellow part. While the head was thus growing, a tail 
was making its appearance, and extending in an opposite direction 
from the head. ‘The egg was now growing smaller while the fish 
rapidly increased in size. The blood in the small artery was now 
flowing along the back and disappearing in the head ; it was truly 
wonderful to see this small stream of bright red blood going on its 
way, drop by drop, without any visible cause. 
The fish (or egg) soon began to show signs of active life, 
wriggling and trying to move itself and its burden of egg food. 
The white, semi-transparent part was now rapidly absorbed, and 
the fish grew with astonishing rapidity, and could soon move about 
by jerks. It would make a great effort and move several times its 
length, when it would remain quiet for some time. No fins had 
as yet appeared, and it still carried a yellow sack about as large as 
itself. It was just learning to swim when the dish was upset and 
observations brought to an end, much after the manner of a 
chapter in a continued story.—/. O. Snyder, in West American 
Scientist. 
