CHAPTER XVI 



FATHERLESS FROGS 



ONE of the most interesting discoveries of recent date 

 in regard to the processes which go on in that all- 

 important material protoplasm which is the physical 

 basis of life and the essential constituent of "cells" those 

 minute corpuscles of which all living bodies are built was 

 made in 1910 by a French naturalist, M. Bataillon, and 

 has been examined and confirmed by another French 

 biologist, M. Henneguy. To explain this discovery, a few 

 words as to well-known facts are necessary. It is well 

 known that if we isolate a female frog at the egg-laying 

 season and let her swim in perfectly pure filtered water, 

 and proceed to deposit some of her eggs in that water, the 

 eggs will not germinate; they remain unchanged for a time 

 and then decompose become, in fact, " rotten." It is a 

 matter of common knowledge that it is necessary for the 

 eggs to be "fertilised" in order that they may start on that 

 series of changes and growth which we call "development," 

 and become tadpoles and eventually young frogs. The 

 " fertilisation " of the frog's eggs is effected in ordinary 

 conditions by the presence in the water of the pond, into 

 wh'ch the female sheds them, of microscopic sperm-filaments 

 (often called spermatozoa, or simply " sperms ") which are 

 shed into the water at the same time by the male frog. 

 The egg (the blackish-brown spherical body, as big as a 



