684 HENRY H. DONALDSON 
down the water determinations by groups, it is quite evident 
that the entire frog begins with a high percentage of water in 
April and May, which diminishes towards the midsummer (Aug- 
ust) and then rises again during the autumn. Moreover as the 
records stand, they suggest that the percentage of water in the 
female, as compared with the male, is higher in the spring, lower 
from July to October and higher again during hibernation. 
It may be added as bearing on this difference according to sex 
that I made a few observations on the percentage of water in the 
ripe ova of these frogs. These were taken early in the spring. 
The determinations are given in table 11. 
TABLE 11 
Percentage of water. Females 
IN ENTIRE FROG IN SAME FROG ~ 
WITH OVA WITHOUT OVA xt ONES 
SEELCS 4 kas heres 76.8 81.4 56.4 
SELES Dien Wh es 76.8 §1.0 | Dae 
SErlGse(acoss hse Meee 76.5 80.8 O2eo 
The average of the values in table 11 is 57.3 per cent which is 
in general agreement with the old observations of Beaudimont 
‘and St. Ange (’47) giving in the eggs of Rana (esculenta?) the 
percentage of 55.7. 
The data serve to show the relatively small amount of water 
in the ova and the effect of the presence of the ova in reducing 
the percentage of water in the entire frog. It is just possible that 
in late summer, at least, small quantities of young ova, considered 
at the time too insignificant to be removed, may have contributed 
to the lower percentage of water in the female at this season. 
For the general course of this percentage during the season, 
as shown in table 10, it is difficult to give a complete explanation. 
Long ago, in his admirable study on the distribution of water, 
v. Bezold (’57) showed that larger frogs (Rana temporaria) had 
a less percentage of water than smaller ones. His series ranged 
in body weight was from 3.0-61.0 gms. and the corresponding 
percentages of water were 79.77 and 74.31, with six intermediate 
determinations. 
