28 THE BIOLOGY OF THE SEASONS 



broods. Every one knows how fond the females are of 

 blood ; the males feed daintily on nectar, if they feed at 

 all, and spend most of their short life in aerial dances. 



One of the irresistible general impressions is that of 

 the abundance of life, especially of minute life. As regards 

 animals, this is seen most convincingly by those who study 

 the sea, with its teeming surface population (the Plankton), 

 or who fix their attention on some particular area, such as 

 a shore-pool or a pond. It is an impression for a lifetime 

 to go into a fish-hatchery and see the rows of rocking 

 cradles in which the young fry are swarming, perhaps a 

 hundred thousand in one box. But from many different 

 sides we get the same impression thousands of tadpoles in 

 the ditch, countless swarms of grubs and caterpillars on 

 land, clouds of mosquitoes rising from the marshes, hundreds 

 of seedlings from one oak tree, an innumerable army of 

 lemmings mustering in the valleys of the Tundra. Life 

 is like an inexhaustible fountain a spring. 



A correlated impression is of the abundance of death. 

 The mortality among the young is enormous. Out of a 

 million oyster-embryos only one survives. Every one re- 

 members Darwin's famous seed-plot in which so many lives 

 began and so few grew up. Out of 533 larvae of the large 

 garden white butterfly collected by Professor Poulton, 

 422 died from ichneumon parasites ; four out of every five 

 a great mortality. The infantile mortality in one of our 

 British towns was 160 per thousand the other year. Every- 

 where we get the impression of a massacre of the innocents ; 

 " so careful of the type she seems ; so careless of the single 

 life." 



Sometimes the thinning process takes strange forms, 

 as in the capsules of the great whelk (Buccinum undatum), 

 whose shell children hold to their ears that they may listen 

 to the fancied echo of the distant sea, or in the vases of the 



