Composition of Eggs. 71 
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thus to have been able to complete the history of one of the most 
curious coloring matters produced by animal organization. 
Of the eggs of Arachnids and Insects.—We submitted to 
analysis eggs of different species of spiders: they contain albu- 
men, fatty bodies and a large amount of a substance precipitated 
y water. Ant’s eggs gave us the same results. These re- 
searches are to be continued in the course of the coming season. 
Of the eggs of Mollusks.—The analysis of Snails’ eggs, which 
we shall complete next season, seems to show us that the eggs of 
Mollusks differ entirely in their composition, from those of other od 
animals. Those which we procured, presented no trace of fats 
they were made up exclusively of hyaloid membranes containir 
a viscous colorless liquid. This liquid contains in solution @ 
ganic azotized substance, not albumen, for it did not coagulate 
with heat. It is precipitated by acetic’acid and dissolves in hy- 
5] 
by way of recapitulation, en- 
favor to state in some general propositions, the most important 
Consequences which seem to be the results of this first work. 
We have shown: 
st. That t ere exist fundamental differences between the com- 
Position of the eggs of animals, and that under this collective 
hame of egg, designating the product of the ovarian apparatus in- 
tended to contribute to the perpetuity of the species, very diverse 
bodies are comprised different as possible from one another. — 
2nd. That among the vertebrated animals, the eggs of birds, 
of reptiles, and of fish, present in their composition, differences 
Which the simplest analysis cannot mistake, and besides that the 
°888 of Sauria and Ophidia bear great analogy to those of birds, 
eng the eggs of Batrachia resemble those of the cartilaginous 
es 
3d. That the eggs of Arachnid and insects differ altogether, 
as “ge Composition, from the eggs of other animals. 
5th. That this extends to the eggs of Mollusks. 
6th. That these differences correspond not only to classes or 
orders; that they extend to natural families even, without stop- 
has | 
but further, that a Carp’s egg is very different from a Salmon’s 
bend that the egg of an Ophidian such as an adder’s, does not con- 
t ; 
a 
