PROPORTION OP THE SEXES. 245 



"a curious fact that the males preponderate very largely in num- 

 "ber over the females. It invariably happens that when the first 

 "rush of fish is made to the net, there will be at least seven or 

 "eight males to one female found captive, I cannot quite account 

 "for this; either the males are more numerous than the females, 

 "or the latter seelr safety by concealment rather than flight." He 

 then adds, that by carefully searching the banks sufficient fe- 

 males for obtaining ova can be found." Mr. H. Lee informs me 

 that out of 212 trout, taken for this purpose in Lord Ports- 

 mouth's park, 150 were males and 62 females. 



The males of the Cyprinidae likewise seem to be in excess; but 

 several members of this Family, viz., the carp, tench, bream and 

 minnow, appear regularly to follow the practice, rare in the ani- 

 mal kingdom, of polyandry; for the female while spawning is 

 always attended by two males, one on each side, and in the case 

 of the bream by three or four males. This fact is so well known, 

 that it is always recommended to stock a pond with two male 

 tenches to one female, or at least with three males to two females. 

 With the minnow, an excellent observer states, that on the spawn- 

 ing-beds the males are ten times as numerous as the females; 

 when a female comes amongst the males, "she is immediately 

 "pressed closely by a male on each side; and when they have 

 "been in that situation for a time, are superseded by other two 

 "males."" 



INSECTS. 



In this great Class, the Lepidoptera almost alone afford means 

 for judging of the proportional numbers of the sexes; for they 

 have been collected with special care by many good observers, 

 and have been largely bred from the egg or caterpillar state. I 

 had hoped that some breeders of silk-moths might have kept an 

 exact record, but after writing to France and Italy, and consult- 

 ing various treatises, I cannot find that this has ever been done. 

 The general opinion appears to be that the sexes are nearly 

 equal, but in Italy, as I hear from Professor Canestrini, many 

 breeders are convinced that the females are produced in excess. 

 This same naturalist, however, informs me, that in the two yearly 

 broods of the Ailanthus silk-moth (Eombyx cynthia), the males 

 greatly preponderate in the first, whilst in the second the two 

 sexes are nearly equal, or the females rather in excess. 



In regard to Butterflies in a state of nature, several observers 



" 'Land and Water,' 1868, p. 41. 



'sTarrell, 'HLst. British Fishes,' vol. i. 1826, p. 307; on the Cyprinus 

 carpio, p. 331; on the Tinea vulgaris, p. 331; on the Abramis brama, 

 p. 336. See, for the minnow (Leuciscus phoxinus), 'Loudon's Mag. of 

 Nat. Hist.' vol. v. 1832, p. 682. 

 17 



