apie 
On the so-called Biogen Liquid. 403 
€ a liquid, which was to apply to the whole animal king- 
ne then i + the liquid, and what part does it play in the his- 
tory of the egg? ‘This liquid is albumen, the albumen which is 
‘formed in the ovary, and to judge rightly of the part which it 
takes in the formation of the egg, some aint considerations 
upon the primitive state of eggs are here necessary. 
Prof. Agassiz} has already reminded us that the point of depart- 
ure of the egg is the same as that of the cells of the organic tis- 
sues. ‘There is a period when the ovule is only a minute cell. 
More recent observations confirm these first results. To know 
the origin of the egg, we must then ascend to the origin of cells. 
There are primordial cells, and derived cells. The experiments 
of Dr. Ascherson,{ have taught us that primordial cells are formed 
of two substances; of an oily substance and of albumen. Cells 
perfectly like rimordial organic cells can be made artificially by 
bringing an os liquid into contact with albumen, although the 
albumen and the oil or oily matter show a perfect continuity of 
substance when we examine them separately. But bring them 
in contact, and cells are formed immediately. Every physiologist 
can repeat these experiments, and ought to do it. 
Primordial cells once formed in the manner above indicated, 
another phenomenon presents itself. They become nucleated, 
and these nuclei enlarging, give birth to derived cells. 
Thus derived cells are malishien by the growth of the nuclei, 
according to wr researches of Mr. Martin Barry,$ of Prof. Agas- 
siz and my o and whenever the third generation appears, the 
parent cell ‘al ns allows its contents to escape ; it is in this 
Way that they increase in number 
vw the only difference there is between the cells of the tis- 
and eggs, is that in these last the parent cell never bursts,|| 
the pamcaial cell preserves within itself all the subsequent gen- 
erations of derived cells; which by their paper eer form the 
substance out of which the new individual is 
Applying now this knowledge in a more sposin! manner to the 
development of eggs, we can reply to the question asked above 
Viz., what part does the albumen play? 
* If the Biogen is so general, I sb ask ai it was not shown in the Sigalion 
and the Sabella of w vest Desot also spei 
tures o Sy eotniee as 
} Ueber den cf Saar path Niitzen der att und iiber eine neue auf deren 
mitwirkung be, e und durch mehrere neue hen unterstiitzte Theorie 
der Zellen —. Miiller’s Archiv. fur Anatomie Physiologie, re. —— 
pt lus de l'Institut, vol. vii, 1838, p. 837. (Sur Cusage ph gique de 
corps 
1 Third Series. 
iF mean, at eieuason aga the new individual is not ready to escape out of 
ge. 
