PROGRESS IN BIOLOGICAL INQUIRIES, 1926 617 
While the fresh-water smelt fishery is not extensive, and is localized, being 
almost wholly confined to Lake Champlain, the fish present several problems 
with which I have been engaged; but I will discuss only one of them at this 
time. This problem pertains to two apparently distinct size groups of smelts, 
which oceur in the same lake. Other lakes apparently contain only one or the 
other size group. The difference in size is conspicuously manifest as the fish 
ascend inlets to spawn. In Sebago Lake, for example, the large form ranges 
in length from 8 or 9 inches up to 15 inches, or more, and averages, perhaps, 
around 12 or 14 inches. The maximum length of the small form is less than 
6 inches and the average between 4 and 5 inches. 
The principal question concerning these two forms is whether they represent 
distinct species, subspecies, or races, or not, or whether the small form is only 
the juvenile of the large form. There is some evidence that they are distinct. 
The breeding run of the large form occurs earlier than that of the small form. 
At Greenlake, Me., for example, where both sizes occur, the large form spawns 
in the last of March or early in April and the small form in May. The feeding 
habits and food of the two forms appear to differ. In Sebago Lake the large 
form has been found to subsist largely upon young smelts and the small form 
of smelt, while the small form eats Hntomostraca almost exclusively. 
The large form of Greenlake, transplanted in Michigan lakes, has be- 
come established in some of them, and, according to Creaser, no small form 
has been observed there. With considerable data on hand, an attempt was 
made to ascertain to what extent, if any, this evidence is supported by structural 
characters. 
As in the case of the marine smelts, proportional measurements and counts 
were made in the same way. These show some differences. Thus, for example, 
the small form has a proportionately shorter head, the distance from the snout 
to end of maxillary is shorter, and it has more gill rakers than the larger 
smelt. A comparison of the probable errors of the means, made by Dr. Willis 
H. Rich, in each of these shows that they are unquestionably significant; but 
just what they signify is hard to say, as the apparently distinguishing structural 
characters of the small form may be those of the juveniles. It has not yet been 
observed, at least in my collections. 
However, aS a general rule the heads of the young fish are proportionally 
longer than those of older fish, and the reverse is the case in the instance in 
question. The large form is structurally more like the salt-water smelt, and 
- the two have virtually the same number of gill rakers. 
Comparison of the small form of fresh-water smelt with the salt-water smelts 
shows that in those particular characters they differ from one another in 
almost the same way that the small form differs from the large form; but 
scale readings show that the majority of the breeding small form are 2 years 
old, with a few 3-year-olds, while the smallest of the large form thus far 
examined are 3 years old. 
There are other situations that complicate the problem, but those stated will 
suffice for the present. 
The practical importance of a solution of the question lies in the fact that 
only the small form, with perhaps young of the large form, is eaten by larger 
food and game fishes. In stocking waters with salmon it has been customary 
to introduce smelts for salmon food in the same waters. If smelts are to be 
distributed thus for food for other fishes, the small form would be the better 
fur the purpose, for in its relation to the young of some other fishes the large 
smelt is known to be a formidable predator in some waters. So, pending a 
positive solution of the problem, perhaps it would be as well to regard the two 
forms as distinct and to distribute only the small form; for if it is distinct the 
desired end would be attained, and if the form is simply a juvenile of the 
large form, the same results would follow as if the large form were distributed. 
Mr. Rapcuirre. I would like to ask Doctor Kendall a question. 
He called attention to the fact that there is no protection for smelt 
in the breeding season. Would it be possible to take smelt in any 
other season ? 
Doctor Kenpaty. That is when the commercial fisheries are carried 
on outside of the breeding season. 
Mr. Rapcuirre. Carried on outside the breeding season ? 
Doctor Krenpatyu. About the middle of September or the first of 
October the season begins and continues until March. 
