62 THE BIOLOGY OF THE SEASONS 



isusuallya single cell, but it is an acorn a formed young thing 

 which falls from the oak tree. The salmon spawns on the 

 gravelly bed of the river, but to the mammalian mother a 

 child is born. There is progress not merely to viviparity, 

 but to bringing forth an offspring at a more and more ad- 

 vanced stage. The embryonic period tends to swallow up 

 the larval period. The advantage is plain, for, other things 

 being equal, the less weak and helpless an organism is when 

 it leaves its parent, the greater are its chances of surviving. 

 Robert Chambers, the author of the Vestiges of Creation, 

 made much of this sound and simple idea. There is pro- 

 digious infantile mortality among many of the lower animals 

 especially among those which have no parental care either 

 conscious or unconscious. We need only recall that the 

 conger-eel is said to have about ten millions of eggs. Part of 

 the object of fish-hatcheries is to shelter the developing em- 

 bryos and larvae until they are able to do a little in the way of 

 fending for themselves. It has been suggested that one of 

 the reasons why the giant reptiles disappeared from off the 

 face of the earth was that their eggs were persistently 

 devoured by egg-eating birds and mammals. 



The seeds which are so numerous in the ground so 

 numerous that Darwin reared eighty seedlings from a single 

 clodlet on a bird's foot represent an enormous store of 

 potential energy. They have a long history behind them. 

 " Formed in the warmth and brightness of last summer's sun, 

 ripened in the glow of Autumn, they fell to the ground, were 

 carried hither and thither by trickling runlets of water, by 

 the winds, by animals, and scattered over new pastures. 

 Through the long chill of winter they remained asleep; but not 

 dead slow preparation was being made for the new day." 1 



While a few seeds, such as those of poplars, must ger- 

 minate at once (i.e. in a few weeks) if they are to develop at 

 1 Study of Animal Life, p. 127. 



