ORIGINATION OF LIVING BEINGS. 73 



meat with some very fine gauze, and then he exposed 

 it to the ^ame conditions. The result of this was that 

 no grabs or insects were produced ; he proved that the 

 grubs originated from the insects who came and de- 

 posited their eggs in the meat, and that they were 

 hatched by the heat of the sun. By this kind of inquiry 

 he thoroughly upset the doctrine of spontaneous gene- 

 ration, for his time at least. 



Then came the discovery and application of the 

 microscope to scientific inquiries, which showed to 

 naturalists that besides the organisms which they 

 already knew as living beings and plants, there were 

 an immense number of minute things which could 

 be obtained apparently almost at will from decaying 

 vegetable and animal forms. Thus, if you took some 

 ordinary black pepper or some hay, and steeped it in 

 water, you would find in the course of a few days that 

 the water had become impregnated with an immense 

 number of animalcules swimming about in all directions. 

 From facts of this kind naturalists were led to revive 

 the theory of spontaneous generation. They were 

 headed here by an English naturalist, — Needham, — 

 and afterwards in France by the learned Buffon. They 

 said that these things were absolutely begotten in the 

 water of the decaying substances out of which the 

 infusion was made. It did not matter whether you took 

 animal or vegetable matter, you had only to steep it in 

 water and expose it, and you would soon have plenty 

 of animalcules. They made an hypothesis about this 

 which was a very fair one. They said, this matter of 

 the animal world, or of the higher plants, appears to be 



