4' 
The Embryology of Patella. 
Fig. 1, while the inner surface is smooth. *) The larger pits are 
sinrply indentations in the outer surface of the chorion and are 
not connected with or extended into fine lines or tubes. None of 
tbese dots nor the fine lines connected with them have anything in 
the nature of a micropyle, which is situated at the animal pole and 
consists of a funnel-shaped projection of the chorion with a large 
irregulär opening at its summit. Within this opening were a number 
of highly refractive globales, which greatly interfered with the 
observation of the fecundation and formation of the pole globules. 
About ten minutes after removing the ova from the ovaries 
the pole globules appear as two colorless and transparent pro- 
longations arising from the surface of the ova at the bottom of 
the funnel shaped micropyle, and extending upward towards its 
opening. PL 1, Fig. 4. They are of enormous size and when living 
appear structureless, but upon the addition of acetic acid take on 
the turbid appearance characteristic of protoplasm when treated 
with this reagent. At first they are of the same shape, long and 
irregulär, PI. I, Fig. 4; but finally one becomes rnuch larger than 
the other, its distal extremity increases in size and at the same 
time assumes a globular form, while the proximal part is reduced 
to a slender neck. Upon treatment with glycerine and acetic acid 
a small indistinctly marked nucleus surrounded by radiating proto¬ 
plasm may be observed in the centre of the swollen end of the 
pole globule. PL I, Fig. 6. The other pole globule at first approxi- 
mately straight and club shaped, PLI, Fig. 4, finally becomes 
very much curved and twisted; no nuclei could be seen in it, 
Two pole globules were usually present, but in abnormal cases I 
have observed as many as four or five, only one of which however 
had the peculiar globular extremity, while the remaining ones were 
elongated and more or less curved. By the end of an hour the 
nbcks of both pole globules were very much reduced in size and 
finally became so slender, that a very slight jar was sufficient to 
break their connection with the ova. 
I had often seen tbese detached polar globules without 
knowing what they were, and remember distinctly having seen 
several in division, although unfortunately at the time I failed to 
make drawings of them. 
t) On one or two occasions I have observed a very thin, transparent and 
strnetnreless membrane surrounding the chorion, from which it was separated by a 
large space. Whether it was always present forming a second chorion and only 
to he seen when thus disiended I am unable to say. 
( 152 ) 
