398 MALL. (Vox. XII. 
is considerably more rapid than the dog’s, as the period of 
gestation is but thirty days. 
Recently Selenka has given some of his results relating to 
the development of the monkey. The most valuable specimen 
relating to the early development of higher animals was unfor- 
TABLE OF AGE AND SIZE OF THE DOG’S OVUM. 
(COMPILED FROM BISCHOFF.) 




DIAMETER OF 
AGE. Deere Os EMBRYONIC STAGE. 
f Mass. 
I day. 15 mm. I cell. 
2 days. sta as 2 cells. 
3 “ce 14 “cc 4 “ce 
4 “cc 16 “ I2 “c 
5 “ .16 “ec 64 “c 
(Xo shes Mulberry. 
7 “ .20 “ ity 
8 “cc .21 “ “c 
9 “ 28 “ “ 
On 3 oeto) et: .07 mm. 
meee G. ie 6 juley 
2 “ 2. “ 2 “cc 
13 “ 3: “ +43 “ 
14 “ 4. “ 5 “cc 
I 5 “ 5. “ee he “ 
16 “ 5: “ 2. ““ 
164 6c 6. ““ 3. “ 


It has been somewhat difficult to compile this table, as Bischoff’s measurements 
are all given in Paris lines. My measurements are taken in great part from his 
figures, and I think that these are very accurate. 
tunately lost, but its age and dimensions are preserved for us, 
and are of value in the determination of the age of human ova. 
The ovum came from a monkey kept in confinement which was 
killed eight days after copulation. If we estimate one or two 
days required before fertilization, this ovum cannot be over 
seven days old. This suggests that the early stage of this 
variety of monkey is developed more rapidly than that of the 
dog. 
o 
