BLOOD OF FRESH-WATER MUSSELS 
517 
Table 5. — Average blood sugar values for 10 species of fresh-water mussels 
Scientific name 
Common name 
Number 
of 
Number 
of 
determi- 
nations 
Blood sugar in milligrams per 100 
cubic centimeters of blood 
mens 
Minimum 
Average 
Maximum 
Buckhorn 
2 
6 
34 
58 
74 
Pimple back 
1 
3 
20 
28 
34 
Maple leaf 
1 
3 
20 
23 
25 
Lady finger 
1 
3 
34 
37 
43 
Southern floater 
6 
14 
7 
16 
61 
Squaw foot ___ 
1 
3 
8 
16 
20 
Three-horned warty-back. .. .. 
1 
3 
20 
28 
43 
Pink heel splitter __ 
2 
6 
34 
47 
65 
6 
18 
8 
48 
93 
Lake Pepin mucket 
1 
3 
10 
17 
22 
22 
62 
32 
INORGANIC SALTS 
Since the pioneer work of Ringer (1882) on the inorganic salts of the blood, it 
has become well established that the chief inorganic salt of the blood of all animals is 
sodium chloride, and that in pfysiological balance with this salt are much smaller 
quantities of potassium and calcium salts, usually the chlorides. As qualitative 
tests on the blood of the species of North American mussels under consideration 
showed the presence of sodium, potassium, calcium, and magnesium, determinations 
of blood sodium by the pyroantimoniate method of Kramer and Tisdale (1921) and 
of the blood calcium by the oxalate method of Clark (1921) were made, the potassium- 
magnesium fraction being computed by difference. The data from these determina- 
tions are listed in Table 6. 
The range between the maximum and minimum for both the sodium chloride 
and calcium chloride in the mussel blood was large when compared with the variation 
in these salts tolerated in dog blood or human blood, and it was only through the 
experimental tests (v. i.) that a satisfactory explanation of this variation in mussel 
blood was obtained. Without going into the experimental data here, it may be 
stated that it was found that the salt content of the blood of fresh-water mussels 
could be modified by the activity of the animal and by the environment in which the 
animal was held. The values in Table 6 represent, for the most part, blood from 
mussels just removed from the water; and as it was noted that a considerable concen- 
tration of the blood could be effected by the animal when the mussel was merely 
kept in the air for a time, the average values in Table 6 are lower than might be 
expected from the maximum values given there. 
Table 6. — Per cent of sodium, calcium, and other salts in the blood of fresh-water mussels 
Scientific name 
Common name 
Sodium as sodium 
chloride, per cent of 
whole blood 
Calcium as calcium 
chloride, per cent of 
whole blood 
Potassium, 
magnesium 
and other 
salts by 
difference, 
average 
Total 
ash, 
averag 
Mini- 
mum 
Aver- 
age 
Maxi- 
mum 
Mini- 
mum 
Aver- 
age 
Maxi- 
mum 
Anodonta corpulenta 
Lasmigona compressa. ... 
Proptera alata .. 
Lampsilis siliquoidea pepinensis..- 
Average 
Slop bucket. 
Heel splitter 
Pink heel splitter 
Lake Pepin mucket. 
0. 0310 
.0505 
. 0469 
.0964 
0. 1013 
. 1092 
. 1144 
. 1125 
0. 2210 
.2289 
.2778 
. 2950 
0. 0087 
.0103 
.0130 
0. 0187 
.0404 
.0225 
0. 0825 
.0859 
. 1060 
0. 0050 
.0009 
.0204 
0. 1256 
. 1496 
. 1573 
. 1820 
. 1093 
.0272 
.0090 
. 1539 
Note.— F igures in this table are from 60 determinations. 
