NATTJKAL HISTOKY, TOKONTO KEGION 



deep water into shoal water near the shore ; towards 

 midsummer they retreat to the deep and cold parts 

 of the lake, where they spend most of their time. In 

 the autumn they again move in towards the shore, 

 seeking their spawning grounds; these are chiefly 

 rocky reefs and shoals, composed of what is known 

 as honeycomb rock. It is said ' that gravelly and 

 sandy shoals are sometimes resorted to for spawning 

 purposes, but this is doubtful. Spawning takes place 

 in October and November, and may possibly be 

 extended by some individuals, or under exceptional 

 circumstances, into December; both the time of 

 spawning and of incubation depend largely upon the 

 temperature. The autumn movement commences in 

 September, but does not become general until Octo- 

 ber; the fish then continue to run in greater or less 

 numbers until the spawning is ended, when they 

 again retire to deep water for the winter. It is a 

 curious fact that even during the spawning season 

 a large number of Whitefish are always to be found 

 in the deep water, but there is no evidence that they 

 ever spawn there. 



26. Cisco. Lake Herring. Argyrosomus artedi 

 (Lesueur). The Cisco was formerly common in 

 Lake Ontario. Of late years, however, it has not 

 been taken there in any quantity. Its spawning sea- 

 son is in November and early December. 



27. Long-jaw Herring. Lake Herring. Argyroso- 

 mus prognathus (H. M. Smith). This fish may read- 

 ily be distinguished from any other Whitefish found 



