Composition of Eggs. 69 
Of the eggs of Crustacea.—Coloring matter of the Crustacea. 
The Crabs of our soft waters and Lobsters have supplied the eggs 
necessary for our researches. Lobsters, carrying from fifteen to 
twenty thousand eggs under their abdominal appendages, are the 
most convenient for the kind of researches which we have un- 
erlaken 
Their eggs do not contain ichthulin; no sort of granules are 
fonnd in them. ‘They are essentially formed of an albuminous 
and saline liquor, holding some fatty bodies suspended in it. 
albumen of the eggs of Crustacea seems to us different, in some —__ 
respects, from the albumen of other eggs. Its coagulation be- 
gins about 74° C.; the sindy of this substance will uecessari 
nd place in the work which we are now preparing on albumin- 
ous substances. ‘€ : 
We have also studied the Sea Lobster (Palinurus). This 
Crustacea, as plentiful as the ordinary Lobster (Homardus) on 
granite shores, and not touching the chalky cliffs,is very uncom- 
mon in the North. The Sea Lobster does not seem to pass 
the Islands of Ushant, and is not found in the British Chan- 
nel. Further, it is very common on the rocks of Bretagne. 
It lives ata much greater depth t 1an the common Lobster, for 
It is necessary, in order to take them, to let down the baited 
hooks to a depth of Prouty fathoms. ‘The eggs of these Crus- 
tacea are very small, hardly as large as a seed of the poppy. We 
_ Mave counted about 130,000 of them under their abdominal ap- 
Pendages. We had, in the early part of March, a living Sea Lob- 
ster, whose eggs were so developed that the two black eyes of the 
little foetus were distinguishable through the shell. We have to 
fegret that we could not save it alive, so as to see the young hatch, 
to follow the phases of their metamorphosis. Science already 
sses some observations made on the embryo of the Lobster, 
but it has none as yet registered on the development of the eggs 
of the Sea Lobster, and many other Crustacea. 
how it has not been conveniently studied, because the asta 
always presented it in a state mixed with fatty bodies, and besides, 
men of the eggs of Crustacea; by heating the liquid, the _— 
minous matter coagulates, carrying with it, in the shape of a lake, 
the coloring matter, which is then of a very beautiful red. The 
Precipitate is retaken by the alcohol, which dissolves the col- 
The detection of this coloring matter, in the egg of the Crus- 
) ng matter, int 
tacea, is undoubtedly an interesting fact, if it be remembered that 
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