534 
BULLETIN OP THE BUREAU OF FISHERIES 
192 hours, one at 168 hours, and two at 144 hours, seem to be exceptions to this state- 
ment in the series given. These animals present an interesting complication as all 
were moribund. Moribund animals in calcium solutions displayed the same rise in 
blood specific gravity and loss of blood alkalinity as moribund individuals in any 
other series. This suggests that the buffering of acid products in the body of the 
mussel draws on calcium in the body rather than that in the environment. 
Table 16 . — Specific gravity and pH of the blood of fresh-water mussels in solutions of calcium salts 
CALCIUM CHLORIDE, 1.00 PER CENT 
Scientific name 
Common name 
Hours of 
exposure 
Condition of animal 
pH 
Specific 
gravity 
Yellow sand-shell 
24 
Dead 
Do - - 
do 
24 
do 
Do - 
do 
24 
do 
Do 
do 
24 
7. 5 
1.0038 
Do 
do 
24 
__ .do 
7.3 
1.0055 
Three-ridge 
24 
Dead .... 
CALCIUM CHLORIDE. 0.50 PER CENT 
Southern floater 
24 
48 
48 
Heart beating ... 
7.5 
8. 1 
1.0037 
1.0032 
Do 
do 
do 
Do 
... .do . 
Dead _ 
Yellow sand-shell . 
72 
Heart beating. 
7.6 
1. 0027 
Do 
do 
96 
. . .do __ 
7.3 
1.0029 
Three-ridge .... 
168 
Moribund. . 
7.0 
1.0045 
Yellow sand-shell 
192 
Heart beating.. 
7. 6 
1. 0032 
Do _ 
do 
216 
do 
7.3 
1.0031 
Do 
do 
244 
do 
7. 7 
1. 0033 
Do 
do . _. 
268 
_ __do 
7.4 
1.0034 
CALCIUM CHLORIDE, 0.25 PER CENT 
Yellow sand-shell . . .. 
24 
Heart beating 
7.7 
Do 
do 
24 
do 
Do 
do ... 
48 
do 
8 0 
Do 
do 
48 
do 
7 Q 
Do 
do 
48 
do 
7 6 
Do 
do ... 
72 
do 
7 4 
Three-ridge 
96 
do 
7.9 
Lampsilis anodontoides ._ ... 
Yellow sand-shell 
120 
Dead 
Do 
do 
120 
Heart beating. 
7 8 
Do . 
_ ...do 
144 
Moribund 
7 
Do 
do 
144 
do 
7 
Do 
do 
168 
Heart beating. 
8 O 
Do 
do 
192 
do ~ 
1 F> 
Do 
do 
192 
Moribund 
7 1 
216 
Heart beating. 
8 1 
Do 
do 
244 
do 
8 1 
Do 
do . 
244 
do 
8 1 
Do 
do 
268 
. ..do 
8 9! 
Do 
do 
268 
8 9 
Do . 
. ...do 
268 
8 n 
Slough sand-shell 
408 
.. ..do 
8 1 
Three-horned warty -back 
408 
7 Q 
Buckhorn 
408 
7.4 
1. 0027 
CALCIUM CHLORIDE, 0.10 PER CENT 
Slough sand-shell 
72 
Heart beating 
7 8 
i noaa 
Buckhorn ... 
96 
7 7 
Slough sand-shell 
412 
7.8 
1.' 0013 
The calcium salt solutions were conspicuously less toxic than any of the other 
groups of salts studied, judging by the survivals and by the small number of moribund 
individuals found. In connection with the toxic action of the calcium salts it must be 
stated, however, that these observations on adult mussels do not apply to the glochidia. 
Adult females were found to tolerate solutions of calcium salts which greatly length- 
ened the closing reaction time of the glochidia which these same mussels were carrying 
