No. 548] ORNAMENTATION IN FISHES 



475 



length, though seldom more. Further, I have every rea- 

 son to believe these small fish were also spawning with 

 the large ones, as I captured specimens of similar dis- 

 parity in the same waters in the spawning-season. That 

 many males spawn without ornamentation also appears 

 likely. No tuberculated females were found. 



The chub sucker {Erimyzon sucetta oblongus) has 

 quite pronounced sexual differences, the spring males 

 showing usually three large tubercles on each side of the 

 snout, the anal rays tuberculated, and usually the last 

 rays more or less incised. These characters only appear 

 in males over five inches, and until the maximum size 

 (eleven inches) is obtained. 



The red horse (Moxostoma), with its numerous species, 

 often exhibits the anal fin tuberculated (M. macrolepi- 

 dotum). I have not obtained recent material, however, 

 for these studies. 



In conclusion the following may be stated. 



First. The disposition of the tubercles in the orna- 

 mentation of breeding males is not always complete in 

 the known design sometimes attained by certain in- 

 dividuals. 



Second. The development of the tubercles may obtain 

 m comparatively small or young individuals provided 

 they are sexually mature. Tubercles occur, so far as I 

 have observed, in the very young, especially in those 

 species which undergo considerable transformation in 

 certain apparent generalized characters, such as the 

 development of the lateral line, change in coloration from 

 a banded or spotted color-pattern to a more uniform tint, 

 etc. 



Third. The tubercles are subject to individual char- 

 acteristics in being retained or lost for a greater or 

 shorter period after the spawning season. 



Fourth. The adult male alone in most species exhibits 

 the tubercles, and though occasionally also present in the 

 female of some species the latter seldom assumes equal 

 development in other respects, such as bright pigment, 



