on 
Composition of Fggs. 47 
amination, we saw one of these ovoid grains pointed at both ends. 
Another had the two long straight sides, ternrinating in two iso- 
celes triangles; it was the figure of an elongated hexagon. he 
hound-fish (Squalus mustelus, Lin.), smaller than the “ Melan- 
dre,” has grains of ichthin almost as large as those of the latter. 
They are five hundredths of a millimetre ; their form is different 
from all the others. These grains are round, but often united in 
the most varied forms. The Bounce (la ronsette, Squalus ca- 
nicula, Lin.) has rectangular grains and obtuse angles, very like 
those of the Ray; their longer side is four hundredths of a mil- 
limeter. The angel-fish (l’ange, Squatina angelus, Dum.) has 
as large grains as the Squalus mustelus; they are elliptical like 
those of the shark, and as large, for they are six hundredths of a 
millimeter. We conclude then, from the comparison of the forms 
of these grains in the different species cited, that the oviparous 
species like the Ray and Bounce, have more or less rectangular 
grains, and are very much alike, while the Cartilaginous viviparous 
Species, like Torpedos and Sharks, generally have oval grains ; 
that if the development of the ovula influences the largeness of 
the grains of ichthin, the size of the fish has no effect on the size 
color: the two latter properties clearly establish the difference 
between ichthin, albumen and vitellin, All the concentrated 
acids dissolve ichthin; when they are dilute, they do not act 
upon it, excepting acetic and phosphoric acids, which immedi- 
ately dissolve grains of ichthin, even when greatly diluted with 
water. Solutions of potash and soda are slow solvents of ich- 
thin. It is insoluble in ammonia. Grains of ichthin when 
burnt, leave no ashes. When the ease with which ichthin can 
be obtained from the eggs of certain fish is considered, and when 
it is seen that grains of ichthin, by the regularity of their form, 
offer all the characteristics of a really pure principle, it is impos- 
sible not to consider it as one of the most interesting substances 
in the animal organization. Ichthin, when analyzed, gives the 
following composition : 
L It. HT. Iv. v. VI. 
Amount of material, 0-452 0427 0282 0-228 0332 0406 
Water, - . . 0-975 0800 0195 07150 
Carbonic acid, - - 0845 0800 0520 0420 
Azote, 0049  0:062 
The results give the percentages : 
oo. SB 510 502 50" 
steele | 7 eee 78 7-6 13 
Azote, Bogie : ae Tae 15-4 
