EARTHWORM STUDIES. 259 



The egg of the Earthworm is never deposited in a well-formed 

 nest. As a rule each specimen is found at a greater or lesser 

 distance from its neighbour. As it is not laid in the open air, on 

 the branches of trees (as the eggs of many insects are), or on the 

 surface of the soil, like the eggs of the Ostrich or Peewit, but in 

 damp places under the bark of trees, under stones by streams 

 and ponds, or deep down in the moist soil, special provision has 

 to be made for its development amid such peculiar surroundings. 

 Or perhaps it would be more correct to say, that as the conditions 

 differ so does the provision for meeting them. 



If the eggs of a bird or fowl be varnished so as to exclude the 

 air, or if they are enclosed in vessels, or buried in soil at a con- 

 siderable depth, the young will never be hatched ; yet here is an 

 egg which can only be hatched when it is kept moist and cool, 

 and one which may be buried at a depth of some inches, or even 

 feet, in earth or under water, and yet retain its vitality. 



The egg of the Earthworm is seldom more than a quarter of 

 an inch in length, and, as it is usually oval, the shortest diameter 

 is only about half that length. It was long ago pointed out that 

 eggs almost invariably remain during the hatching period the 

 same size as they were when first extruded, but here is a curious 

 exception to the rule. We should look with amazement on a 

 Pigeon's egg which increased in size till it became as large as a 

 hen's egg during the time when the mother bird was sitting upon 

 it, but this is exactly what happens in the egg before us during 

 the hatching period. It both lengthens and widens, and we shall 

 have to enquire how this is possible. 



The naturalist is already well aware of the fact that when an 

 animal regularly lays a large quantity of eggs of minute dimen- 

 sions, the offspring is almost invariably unlike its parent, and has 

 to undergo sundry transformations, changes, and developments 

 before arriving at any degree of perfect resemblance to the adult 

 form. Conversely, as in the case of birds, when a few relatively 

 large eggs are laid the young usually emerges with a strong 

 resemblance to its progenitor. The reason is obvious. A good 

 deal of material is needed within the egg in order that a perfectly 

 developed brood may emerge, and when the parent is compelled, 

 through the struggle for existence, to launch a bevy of young on 

 the sea of life, it cannot possibly fill the pockets of each (to speak 



