53 
been subjected fails to show an}^ very constant ratio between the two. 
Under normal conditions the longest egg period recorded in the spring 
was eight da}' s, and in the fall seventeen days. 
EFFECT OF REDUCED TEMPERATURES. 
Aside from the numerous records of the length of the egg period at 
different temperatures under normal conditions, a few experiments 
were made to ascertain the effect of much reduced temperatures on 
18 
17 
16 
15 
14 
13 
12 
II 
10 
7 
6 
5 
/I 
APR. 
MAY 
JUNE 
JULY 
AUG. 
SEFT 
OCT 
NOV 
18 
\7 
16 
15 
14 
13 
12 
II 
10 
8^ 
7 
6 
5 
4 
3 
2 
1 

/ 
/ 
/ 
/ 
/ 
/ 
' 
1 
/ 
^\ 
/ 
\ 
/ 
V 
/ 
^ — ^ 
J 
3 
2 
1 

X 
--^s^^ 
^_^^ 
/^ 
^ 
^.^.y 
^^''^ 
APR. 
MAY 
JUNE 
JULY 
AUG. 
SEPT. 
OCT 
NOV. 
Fig. 4. — Diagram showing relative length of o.'g^ stage during season of 1904, Paris, Tex. (original). 
embryonic development. The first series consisted of six lots which 
were placed in an ice-box where the temperature varied irregularly, 
between 50° and 60° F. The appended table summarizes the results: 
Table XV. — Effect of low temperatures on embryonic development. 
Num- 
ber of 
eggs. 
Age of egg. 
Time in 
ice-box. 
Remarks. 
4 
1 
428 
Brown ring present . . 
About to hatch 
Newlv laid 
Days. 
13 
2 
lOi 
10 
33 
13 
Eggs showed no development until removed, then hatched 
after 48 hours. 
Egg showed no development until removed, then hatched 
after 3 hours. 
A very few developed the brownish band, a few shriveled, 
and the greater portion remained white until removed, 
when they hatched after 2\ days. 
Were dark at the end of 10 days and hatched on being 
taken out. 
Eggs developed a wide brown band and became orange 
yellow; 12 hours after removal they darkened as if to 
hatch, but shriveled instead. 
After 13 days many were hatching, while about 50 were 
hardly developed. 
Many. 
do 
600 
do 
382 
do 
The effect of much lower temperatures was tested at the Paris ice 
factory, where the maiaagement very kindly placed at our disposal their 
