MIMIC BY. 347 



Sturgeon (Acipenseridce) deposits enormous numbers of extremely 

 minute eggs, the product of a single individual having been 

 estimated at upwards of three millions during a season. This 

 fecundity is necessary to preserve the species, when, apart from 

 other enemies, we read that upwards of fifteen thousand have 

 been taken by fishermen in a single day at one of the fishing 

 stations on the Russian rivers.* Many other instances of great 

 fecundity among fishes might be given, but at least reference may 

 be made to the testimony of Mr. Henry Lee, that a large Octopus 

 produces in one laying, usually extending over three days, a 

 progeny of from 40,000 to 50,000 ; and the same authority, con- 

 firming the observations of Johann Bodasch, found that in the 

 mop-like mass of spawn belonging to a Squid (Loligo vulgaris) 

 there were probably 42,000 perfect young Squids. f 



Among mammals, the Rat is very prolific. Frank Buckland 

 was told by a trustworthy Westminster ratcatcher that the Rat 

 will breed every seven weeks, and that the female will begin to 

 have young as early as fourteen weeks old. X The same author, 

 referring to a little book on the Rat written by a Mr. Shaw, " of 

 ratcatching notoriety," states that " his little dog Tiny, under 

 six pounds weight, has destroyed two thousand five hundred and 

 twenty -five Rats, which, had they been permitted to live, would, 

 at the end of three years, have produced one thousand six hun- 

 dred and thirty-three millions, one hundred and ninety thousand, 

 two hundred living Rats."§ " Every wild Rabbit who lives to 

 old age has probably been concerned during its life as one of two 

 partners in the production of not less than three hundred young 

 Rabbits." Yet in England no perceptible increase is visible, 

 and we must conclude " that out of three hundred Rabbits born, 

 only two survive to middle age, on the average ; the rest being 

 either killed and eaten by carnivorous animals, or (more rarely) 

 dying through inability, for some reason or another, to obtain 

 food. "|| The Hamster {Cricetus frumentarius) possesses mar- 

 vellous powers of reproduction, and frequently appears in count- 



* ' Royal Nat. Hist.' vol. v. p. 514. 



f Cf. H. Woodward, ' CasselPs Nat. Hist.' vol. v. pp. 161 and 166. 



I ' Curiosities of Nat. Hist.' Pop. edit. vol. i. p. 69. 



§ Ibid. p. 70. 



jl Wells and Davies, * Text-Book of Zoology,' p. 128. 



