686 CLARENCE L. TURNER 
The spaces between the ordinates represent intervals of ap- 
proximately thirty days while the spaces between the abscissae 
represent variations of one per cent in the ratio between the 
weight of the testis and the weight of the body. 
The maximum weight of the testis is reached about November 
1. From November 1 to April 1 there is a gradual decline in 
weight. The irregularity in the curve between December 1 and 
March 1 is occasioned by individual variation. During these 
months difficulty was experienced in getting specimens, and it is 
probable that there would have been no irregularity had enough 
material been at hand. The declining curve from March 1 to 
July 1 does not indicate that there is a gradual expulsion of the 
spermatozoa by each individual between these dates, but rather 
that a few fish discharge their spermatozoa as early as March 1 
while others do not discharge until late in May. The curve 
declines as the proportion of those which have discharged in- 
creases. Although the point in question was not verified by 
actual observation, it is probable that each fish has a series of 
discharges, for a great many testes showed different stages of 
depletion during the spawning season. 
No attempt was made to keep separate data for fish of differ- 
ent ages when it was found that specimens varying in weight 
from 60 grams to 300 grams did not offer any essential differ- 
ences from the general course described. 
3. Microscopical anatomy 
The testis is a sack enclosed in a connective-tissue sheath 
which contains a large proportion of elastic elements. Within 
each testis, on its ventral side, is a connective-tissue core, deeply 
imbedded, from which septa radiate. These septa extend to 
and join the testis-wall, dividing the entire organ into lobules. 
This connective-tissue core is somewhat comparable to the me- 
diastinum testis of the higher vertebrates. The cores of the two 
testes converge and fuse posteriorly at the point of fusion of the 
testes. The elastic fibers are very abundant throughout the en- 
tire testis. Two heavy cords of elastic fibers are located in the 
mesorchia which suspend the testes from the swim bladder. 
