194 
from that of the albumen, or, as we may say, at an opposite 
P °74. We may therefore define an egg, so far as chemistry 
can inform us, as a globular accretion of two kinds of fluids, 
albumen and oil, which are situated at opposite sides or 
poles. r 
75. I now present from the same source the perfect egg ot a 
hen, (which has been boiled,) in section,— in which sketch will be 
distinguished the shell, the spirally-wound layers of the white 
(albumen) twisted into chords, which serve as axles, upon which 
the yolk swings and revolves whenever the egg is rolled over, 
so as to keep the side with the white spot ( cicatricula ) upper- 
most, and nearest to the warmth of the hen. 
76. It is impossible, even with prolonged boiling, to harden 
that part of the yolk {v,V) which extends from the white spot 
to the centre. _ , . , . 
77. From Wagner’s Elements of Physiology I take what 
seems to be in some respects a still better representation* 
78. I think it unadvisable to do more than indicate trom 
Wagner the commencement of the development of the perfect 
animal. Every one can folllow up in thought the formation ot 
the members of the perfect animal, “ which in continuance were 
fashioned when as yet there was none of them ” 
79. Here, in the nota primitiva, or primary streak [a), is the 
first indication of the new being after twelve to fourteen hours 
incubation. Another, from Cuvier’s Regne Animal , shows the 
* This is omitted in printing the paper, 
original. 
The reader is referred to the 
