28 The Third and Fourth Generation 



only an inch deep, and some clean sand should be 

 added, so the animals can wiggle up out of the 

 water on to the sand at one side of the dish. 



What has been described in particular for 

 the mandrake and the frog is a universal process 

 among the common plants and animals with 

 which you are familiar. There is a process of 

 reproduction among the lower forms of life by 

 which the adult becomes two or more young by 

 simply dividing into parts, each of which is 

 remodeled into a perfect animal or plant, as 

 the case may be. But in all higher types it is 

 almost universally true that the young are 

 produced from eggs which must be fertilized by 

 the sperm before they will begin to develop. 

 It is evident that the offspring is the joint 

 product of the two parents, a union of two 

 distinct lines of hereditary descent, and as 

 such may manifest characters peculiar to each. 



QUESTIONS 



1. Have you ever found frogs' eggs or toads' eggs ? 

 Can you describe them ? 



2. Have you found the eggs of other animals, Hke 

 flies or turtles or fish ? If so, where ? 



