The Inhabitants of the Aquarium 279 



trees, meadows or marshes. As soon as 

 the eggs appear the fertilization by the male 

 takes place. The eggs, originally small, are 

 surrounded by a gelatinous coating which 

 considerably increases in size as soon as it 

 reaches the water. 



After the mating process, the frog- 

 couples separate and return to terra firma, 

 leaving the masses of eggs where they were 

 produced. After a few days these masses 

 appear as big balls consisting of a large 

 number of glassy round cells with small 

 dark centers, — the embryos. The latter 

 soon grow in size and, according to weather 

 and species, the larva leaves the sheltering 

 egg after between 8 and 14 days, to com- 

 mence life as the well-known tadpole. 



It is most interesting and instructive to 

 observe the growth and development of the 

 embryo from the first day. The originally 

 round little body will soon begin to stretch 

 and change its shape, until a thick, roundish 

 body and a long, strongly depressed tail can 



