BULLETIN OF THE BUREAU OF FISHERIES. 
II4 
By reference to table v the advantages of artificial infection can be readily 
imagined when the small percentage found infected in a state of nature is considered. 
Some one has long ago estimated that in the case of some fishes but 10 per cent of the 
eggs deposited naturally are even fertilized, whereas by artificial means it is now an 
established fact that fully 90 per cent, and even better, is not only possible, but a rule, 
in handling these same fishes. Now in the mussel the eggs are fertilized and the young 
developed ready for their parasitic life while still in the gills of the parent, so that all 
man has to do is find the specific host of a given species, procure that host, and load it 
to the limit, which may exceed the optimum infection of Lefevre and Curtis “ in some 
cases. The simplicity of the proceeding is startling when we consider the ease with 
which the glochidia can be procured, a fair sized mucket (L. liganientina) , for instance, 
producing as many as 3,500,000 young and the niggerhead {Q. ebena) about 350,000. 
Table V. — Fish Caught and Examined for Natural Infection, June to November, 1912. 
Species of fish. 
June-July. 
August. 
September. 
October. 
Noi'ember. 
Total. 
Exam- 
ined. 
In- 
fected. 
Exam- 
ined. 
In- 
fected. 
Exam 
ined. 
In- 
fected. 
Exam- 
ined. 
lu- 
fetced. 
Exam- 
ined. 
In- 
fected. 
Exam- 
ined. 
In- 
fected. 
1 
2 
1 
4 
2 
66 
7 
8 
3 
168 
8 
I 
6 
67 
1 
41 
2 
I 
I 
3 
1 
15 
16 
2 
3 
258 
i>iS 5 
2 
58 
I 
43 
24s 
4 
4 
22 
9 
95 
92 
78 
322 
2 
18 
I 
16 
7 
2 
3 
48 
2 
19 
1 
13 
I 
2 
2 
4 
21 
70 
29 
6 
I 
I 
I 
4 
1 
3 
2 
4 
44 
18 
I 
18 
7 
13 
I 
I 
3 
I 
10 
I 
1 
2 
104 
640 
5 
5 
3 
8 
IS 
I 
I 
7 
30 
I 
s 
144 
278 
I 
I 
3 
12 
I 
4 
I 
9 
I 9 S 
I 
3 
41 
I 
42 
35 
I 
2 
10 
I 
I 
4 
I 
I 
4 
30 
3 
137 
43 
I 
3 
9 
I 
9 
4 
3 
32 
76 
6 
38 
3 
71 
20 
5 
2 
3 
141 
20 
II 
4 
27 
I 
2 
3 
1 
I 
30 
6 
104 
5 
4 
15 
Total 
210 
13 
499 
II 
1.077 
5 
792 
10 
237 
7 
2,815 
46 
o Lefevre, George, and Curtis, Winterton C.: Studies on the reproduction and artificial propagation of fresh- water mussels. 
Bulletin of the Bureau of Fisheries, vol. xxx, p. 159, 
