176 THE DEAGONET FAMILY. 



not only in its gorgeous tints but also in other features such as 

 longer dorsal fin-rays, and a larger head. These differences 

 between the sexes, apart from those of the sexual-organs, are 

 known as secondary sexual characters, and such characters as a 

 rule are not found (except disparity of size) in the fishes which 

 lay pelagic eggs. This is probably connected with the fact that 

 the fishes do not pair but merely shed their milt or ova indis- 

 criminately in the water. The dragonet forms an exception in 

 that the egg of this species is pelagic and yet the secondary 

 sexual characters are very marked. In accordance with this, 

 we find that the dragonets instead of congregating in shoals at 

 the breeding season, pair off and move about in couples whilst 

 discharge of the sexual products is effected. The males are 

 said to be rarer than the females, in the proportion of about 

 1 to 3. 



Two theories have been suggested with regard to the origin 

 of sexual coloration. The bright colour of the males is explained 

 as the result of continued selection by the females of the most 

 brilliantly accoutred males, and thus by the law of heredity the 

 brightest males only reproduce their species, and on the other 

 hand, a protective and therefore sombre garb is more necessary 

 to the females than the males in order that the next generation 

 may be preserved. Young males are occasionally found present- 

 ing the brown coloration usually characteristic of the females 

 only. 



The dragonet appears to spawn from May to August. Eggs 

 are found in most abundance in June, July and August, but 

 some occur in early May (Smith Bank), even at an advanced 

 stage of development 1 . This being the case, the dragonet 

 seems to spawn throughout the summer months, and its breed- 

 ing-season is long. It is one of the species which occasionally 

 discharges eggs in proximity to bhe shore, i.e., within the 

 territorial waters. 



The egg (Plate I, fig. 15) is comparatively small (average 



diameter '025 '03 inch) and perfectly translucent, but is at 



once distinguished by the fact that outside the egg-membrane 



are ' a series, for the most part, of hexagonal reticulations like 



1 A. T. M., llth Ann. Rep. S. F. B. 



