Composition of Eggs. 65 
is printed upon enamelled cards, and the different impressions 
have been found to agree so closely with each other as well as 
with the original plate that no appreciable error is perceived. 
I can not close this paper without expressing my warm thanks 
to Indge A. S. Johnson of the New York Court of Appeals, for his 
cordial sympathy and aid in testing the merits of the ludicator and 
for some excellent suggestions as to its best form for general use. 
I should also express my obligations to the engraver, J. E. Gavit, 
Esq, of Albany. who has spared no pains in making the steel 
plate from which the Indicator is printed as accurate as possible. - 
dl 
a el 
Arr. VIL.—On the Composition of Eggs in the animal series ; 
y Vavenciennes and F'rémy.—Part IILI.* 4 
Eggs of Reptiles. ag 
In the two preceding memoirs, we have given the results of 
our observations on the eggs of Fishes. We have pointed out in 
these egos the presence of the proximate principles, ichthin in 
Rays and Sharks, ichthulin in the species of the uumerous fami- 
lies of osseous fishes, and have directed attention to the important 
fact, that this principle is gradually modified in proportion as the 
&8¢ approaches its maturity, and that it ends by disappearing in 
the egg when it is ready for fecundation, the ichthulin being 
hen replaced by albumen. 
~ We now continue the account of our researches on the eggs of 
other oviparons animals. 
_ “88s of Tortoises —We have examined the eggs of two spe- 
cies of Chelonian reptiles belonging to two distinct genera. Some 
Were hatched by a land Tortoise from Algiers, which M. Dumeril 
as called Testudo Muuritanica. This female has lived for many 
_ years in France, at the house of a resident of Grandville. The 
second is the fresh-water ‘Tortoise of Europe, the mud Tortoise 
(la bourbeuse ) of Danbenton and Lacépéde, which M. Dumeéril 
calls Cistudo Europea. Although these two species of Chelo- 
nians inhabit different countries and climates, the resemblance in 
the constitution and composition of the liquids of their eggs is 
well worth remarking ; but there is a further similarity which we 
hardly expected ; it is that they have a great analogy to those of 
tn ournal de Pharmacie for August, 1854: translated by Dr. Rosengar- 
“tn. For Parts I and II, see last volume, p. 38, 238. 
D Series, Vol. XX, No. 56.—July, 1855. _ 4 
mt 
