brook trout, in proportion to the size of the body. At first 

 they are unable to swim, or even move themselves from the 

 bottom, but in from two to six weeks they begin to rise and 

 swim, although they are from one to two months old before the 

 sac wholly disappears and they become perfectly developed 

 fish. 



After the fish are hatched the mother seldom passes over the 

 bed, as in their then helpless state the motion of her fins would 

 scatter them ; but instead she now swims in circles around it driv- 

 ing away all intruders, such as minnows, crawfish, etc. After 

 the young begin to swim she enlarges the circle until it becomes 

 from ten to fifteen feet in diameter, she then gradually drives 

 them toward the shore into shallow water where she keeps 

 them inside of a half circle, the shore forming the other side. 

 From this half circle all of their natural enemies are carefully 

 excluded, and the fish are allowed to develop. After that is 

 done she scatters them along the shore among the weeds and 

 grass, where, if pursued, they can find hiding places. Then, 

 and only then, does she leave them to care for themselves. 

 They are now from one-half to three-fourths of an inch in 

 length, black in color and very lively, darting out of their hid- 

 ing places and seizing their prey as readily as the older fish, and 

 by the first of October following will be two inches in length. 



I should estimate the average number of eggs in the beds at 

 4,000. Owing to the fact that some of the beds observed were 

 near the mouths of cold spring brooks, where the temperature 

 of the water in the river was much lower than where other beds 

 were located, will account in a great measure, in my opinion, 

 for the variation in the time taken for hatching the eggs and 

 the development of the young fish ; as in some seasons, and in 

 some locations, I have found the young fish developed or weaned 

 in one month from the time that the ova were deposited, and 

 at other times two months were required for the same purpose. 



I have been unable to procure both male and female fish at 

 the proper time to try artificial impregnation, but have 

 repeatedly taken part of the ova from the bed as soon as impreg- 

 nated, and hatched them in dishes, and have kept them there 

 until fully developed. I am of the opinion that very little can 



