62 THE SMALL-MOUTHED BASS 



ence in colour between male and female nearly always becomes 

 evident as spawning proceeds. From a knowledge of these 

 differences between the sexes at this season there can be no 

 doubt of the correctness of the statement that the fish which 

 builds the nest and which subsequently guards the eggs and 

 the young fish is the male. As further evidence of this, on 

 five different occasions the fish which was guarding the nest 

 of the young brood has been taken on the hook and on each 

 occasion has been found upon dissection to be a male. 



Although I have seen the small-mouthed bass on their 

 nests probably hundreds of times and have four times ob- 

 served the spawning in part, and once throughout its whole 

 duration, yet I have never seen a female on or near a nest 

 except when actually engaged in spawning. 



The following account of the spawning is from field notes 

 of the case in which the whole process was observed. The 

 other four cases in which the spawning was observed in part 

 did not differ in any essential way from this one. "On May 

 llth, at 12.30 p.m., a fresh-built nest is found near the outlet 

 of pond 1. It is in about eight inches of water in the open, 

 that is, not within one of the artificial shelters provided for 

 the nesting fish, and near shore. The male fish is on the nest, 

 the water is clear, there is no wind and the sun is shining. 

 The conditions are therefore ideal for observing the spawning 

 habits. A weather-worn batten-door is hastily obtained, a 

 hole is knocked through it, and it is then propped on edge 

 about ten feet from the nest. Through the opening one 

 may observe the nest with field glasses as clearly as though 

 he held it in the hand." 



"The screen is hardly in place before the two fish, each 

 about 10 inches long, are seen, one two yards north of the 

 nest and the other two yards south of it. Both are small 

 fish and at first the sexes can therefore not be distinguished. 

 Presently one of the two approaches the other and urges it 

 into the nest. Both fish are of the usual dark green-bronze 



