FISHES. 387 



season, of deep leaden-black; they then retire from the 

 shoal, and excavate a hollow as a nest. *^ Each male now 

 mounts vigilant guard over his respective hollow, and vig- 

 orously attacks and drives away any other fish of the same 

 sex. Toward hij companions of the opposite sex his con- 

 duct is far different; many of the latter are now distended 

 with spawn, and these he endeavors by all the means in his 

 power to lure singly to his prepared hollow, and there to 

 deposit the myriad ova with which they are laden, which 

 he then protects and guards with the greatest care."* 



A more striking case of courtship, as well as of display, 

 by the males of a Chinese Macropus has been given by M. 

 Carbonnier, who carefully observed these fishes under con- 

 finement, f The males are most beautifully colored, more 

 so than the females. During the breeding-season they con- 

 tend for the possession of the females ; and, in the act of 

 courtship, expand their fins, which are spotted and orna- 

 mented with brightly colored rays, in the same manner, 

 according to M. Carbonnier, as the peacock. They 

 then also bound about the females with much vivacity, and 

 appear by ^^'etalage de leurs vives couleurs chercher d 

 attirer Tattention des femelles, lesquelles ne paraissaient 

 indifferentes a ce manege, elles nageaient avec une molle 

 lenteur vers les mdles et semblaient se complaire dans leur 

 voisinage." After the male has won his bride he makes a 

 little disk of froth by blowing air and mucus out of his 

 mouth. He then collects the fertilized ova dropped by the 

 female in his mouth; and this caused M. Carbonnier much 

 alarm, as he thought that they were going to be devoured. 

 But the male soon deposits them in the disk of froth, after- 

 ward guarding them, repairing the froth, and taking care 

 of the young when hatched. I mention these particulars 

 because, as we shall presently see, there are fishes the males 

 of which hatch their eggs in their mouths; and those who 

 do not believe in the principle of gradual evolution might 

 ask how could such a habit have originated; but the diffi- 

 culty is much diminished when we know that there are 

 fishes which thus collect and carry the eggs; for if delayed 

 by any cause in depositing them, the habit of hatching 

 them in their mouths might have been acquired. 



* *' Nature," May, 1873, p. 25. 



I** Bull, de la Soc. d'Acclimat.," Paris, July, 1869, and Jan. 1870, 



