342 



THE ZOOLOGIST. 



now declining.* This diminution may well take place, for, accord- 

 ing to Prof. Henry Woodward, of the common species Homarus 

 vulgaris, as many as 25,000 live specimens "are often delivered 

 at Billingsgate in one day. If only as many are eaten in the whole 

 of England as in London, this would be at the rate of 50,000 per 

 day, or 18,250,000 annually. . . . From Norway as many as 

 600,000 are received annually." f Marine animals commonly 

 produce far more eggs than insects. The dangers of the shallow 

 seas are so great that a small proportion only of the young 

 animals come to maturity. Hence the enormous fertility of 

 common marine animals, except such as are able to nourish or 

 defend their young. Vast numbers of Zooea are swept into mid- 

 ocean or into tidal rivers, or are devoured. It is only a chance 

 remnant that survives.]: Prof. Mobius says that out of a million 

 oyster embryos only one individual grows up, a mortality due to 

 untoward currents and surroundings, as well as to hungry 

 mouths. § Leuckart calculates that a tapeworm embryo has only 

 about one chance in 83,000,000 of becoming a tapeworm. || 



The fecundity of fish is shown by the following table of the 

 number of ova in different species, as found by Frank Buckland's 

 observations : — 



Name of Fish. 



Salmon. (The average num- 

 ber of eggs in a Salmon is 

 850 to each pound weight) . . 



Trout 



Carp 



Perch 



Weight of Fish. 



lb. 



12 

 1 



14 

 3 

 



No. of Eggs. 



10,000 

 1,00811 

 633,350 

 155,620 



20,592** 



* * Zoologischer Anzeiger,' xvii. no. 454; summarized in 'Nature,' 

 vol. l. p. 553. 



■f- ' Cassell's Nat. Hist.' vol. vi. p. 205 ; also cf. W. B. Lord, ' Crab, 

 Shrimp, and Lobster Lore,' p. 95. — According to Bertram, ' As a general rule, 

 the great bulk of Lobsters are not much more than half the size they used to 

 be' ('The Harvest of the Sea,' p. 274). 



I L. C. Miall, « Nature,' vol. liii. p. 154. 



§ Cf. Thomson, ' The Study of Animal Life,' 2nd edit. p. 43. 



|| Ibid. p. 48. 



IT " There is not a living creature," said Mr. Francis Francis, " which 

 inhabits the waters which does not prey more or less on Trout ova " (" The 

 Trout " (Fur, Feather, and Fin Series), p. 171. 



** The number of eggs produced by this fish has been given as much 

 greater by more recent writers. " Upwards of two hundred and eighty 



