2 78 JORDAN. [Vol. VIII. 



The number of eggs in each ovary and the weight of the 

 ovaries, are indicated in the following table : 



The relative weight of the mature ovaries to the weight of the 

 whole body is about one to nine. The " number of eggs " given 

 in the table is the number plainly visible to the naked eye ; 

 the number visible with even a low power of the microscope is 

 of course far greater than this. The number of large pig- 

 mented eggs measuring approximately one millimeter in diam- 

 eter is about forty per cent, of the number given in the table. 

 All of these pigmented eggs are in ordinary circumstances 

 deposited in a single season ; the number of eggs laid by a 

 good-sized female every year is consequently about 180-250. 



The ovaries of females captured at the close of the breeding 

 season contain no large pigmented eggs, and are stringy, light- 

 colored and greatly shrunken. The weight of the ovaries has 

 greatly decreased as shown in the following table : 



That is to say, about one-tenth of the body weight is dis- 

 charged in the form of eggs every year. It may be noticed 

 also that the weight of females captured at the close of the 

 laying season is distinctly lower than that of females taken in 

 early spring. The average weight of the former is 2.05 grm. ; 

 that of the latter, less the average shrinkage of the ovaries, 

 2.74 grm., while the average length of the individuals com- 

 posing the two groups is about the same. This result is sub- 

 stantiated by other weighings and measurements which it is 

 not necessary to give in detail. There is hence a loss of body- 

 weight, in addition to the direct loss of egg-substance, during 



