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eS PSR Gir sciilyons 
Composition of Eggs. 241 
At the moment of its precipitation the ichthulin is viscous and 
resembles gluten. But the action of the alcohol and ether canses 
it to lose its viscosity, and it becomes then solid and powdery. 
The ichthulin, which in its physical properties differs in every 
respect from ichthin, is very like it in its chemical characteristics. 
It is, like the latter, soluble in acetic and phosphoric acids; it dis- 
solves too in hydrochloric acid, without producing a violet color. 
Its composition is as follows : 
7 , Il. 
Solid matter, - - - 0-283 | Solidmatter, - - - 0253 
eS en 0-205 ee tage 
Carbonic acid, - - - 0545 Carbonic acid, - - - 0495 
Proportion of Azote 
Solid r, 0.838 
Azote, = 2 gnbtas 
Per centages. Per centages, 
Carbon, = - rm 2 £ 525 Carbon, - = = 5 53:3 
Hydrogen, - _ e - 80 Hydrogen, - - 83 
Azote, a - - 15-2 
ephew, - . = - 06 
Bilphur, 10 
Oxyge . - = 29-7 
_ Prom these analyses it follows that ichthulin differs in compo- 
Sition from ichthin : ‘jit approaches on the other hand that of albu- 
men, and like it, contains sulphur and phosphorus. From these 
facts, it follows that the egas of fishes of the family of Cyprinide, 
when only a little developed, contain, witha soluble substance ich- 
thidin, a liquid strongly albuminous holding in solution mineral 
“a'ts, some ichthulin, and suspended in it phosphoric fat. After o 
taining these results, it seemed interesting to compare with eggs 
inthe state of ovule the composition of eggs of the same sort 
completely formed, detached from the ovarian lobules and free in 
the oviduct. ‘This examination has brought us to the establish- 
ment of this very important physiological fact: that is, that the 
Composition of eggs undergoes, with the age of their develop- 
ment, important modifications, even before the laying, and dur- 
ing the time that they remain in the oviduet. It is in fact, a re- 
sult of our analyses, that the eggs of the Carp, entirely formed, 
contain no longer traces of ichthidin; that the ichthidin gradually 
‘Sappears, and that when they are become entirely traysparent, 
these eggs are formed wholly of a liquor strongly albuminous, 
Which holds suspended in it phosphuretted fat. ‘The examina- 
hon of Carps’ eggs while young, has also shown us, that to study 
th ggs of these Cyprinide, it is necessary to guard against put- 
ting them in contact with water, which often dissolves bodies 
Whose presence it is important to establish, and which in other 
Cases, precipitates substances as the ichthulin, which were at first 
dissolved in it, 
Skconp Serres, Vol, XIX, No. 56.— March, 1855. 31 
