Fishes spawn but once each year, and the time and length of the spawning season is not the same for all species. With some species the season is short, while with others it may extend through three or more months. In the latter case those produced the first part of the spawning season are at the end of six months much larger than those which appear at the close. It is therefore evident that the fishes of any single brood by the end of the year will vary greatly in size, often to such an extent that the broods of one season cannot be separated from those of the preceding season; especially is this true of our smaller species. Mr. Moenkhaus, in making a study of the two species of darters, the Sand Darter or "Johnny," and the Log Perch, found by collecting a large, miscellaneous lot of these fishes, from a given locality, that it was possible to separate them in groups according to size of one, two or three years of age, which indicates a quite uniform rate of growth for these two species. Mr. Voris collected a miscellaneous lot of over five hundred specimens of the Blunt-nosed Minnow from Turkey Lake in Indiana, varying from one to three inches in length. These, when separated as far as possible, according to sizes, did not fall into distinct groups of different ages. In my own collecting and study of fresh water fishes I have always been impressed with the difficulty of recognizing the age of fishes, except that the smallest taken was considered to be the product of the preceding spawning season. Here is an interesting question to which but little attention has been given. Any one will find much interest in studying the rate of growth of fishes under different circumstances. We know that the rate of growth is in no way uniform, as is the case with our warm-blooded animals. We also know that among fishes there is no uniform adult size, as there is in case of warm-blooded animals (birds and mammals). In general, we cannot speak of a fish as being full-grown; at the same time there seems to be a limit of size for each species in each body of water, beyond which only a few go. The Chinook salmon we mentioned reach an average weight of twenty to thirty pounds, although individuals are occasionally taken of forty, sixty or even one hundred pounds weight. These large fishes are by no means common, the other species of salmon never attain the size of the Chinook.