240 UTILIZATION OF MINUTE LIFE. 



If a few flower stalks or a handful of green 

 leaves be placed in a glass of water, and allowed to 

 remain there from two to four days exposed to the 

 air and to the light, at the end of that time the 

 water will have assumed a green or brownish-green 

 colour, and on being submitted to examination 

 under the microscope, will be found to swarm with 

 many descriptions of infusoria. How they come 

 there is still a subject of discussion among many of 

 the first men of the day. Some say their eggs or 

 " buds" are constantly present in the air, driven 

 about everywhere by the wind, and develop them- 

 selves whenever they happen to fall upon an appro- 

 priate medium, such as putrefying vegetable sub- 

 stance, etc. Others say that no such eggs are 

 present in the air, but that they form spontaneously 

 in water containing vegetable matter, as the eggs 

 of other animals form in the womb.* 



Lamarck, Oken, Geoffroy St. Hilaire, Bory de 

 St. Yincent, Darwin, and other distinguished natu- 

 ralists, look upon certain infusoria (Monades) as the 

 fundamental organic substance from which all higher 

 organisms have been progressively developed. Na- 

 ture created Monades, the most simple form of 

 infusoria, from the gradual perfection of which, 

 through myriads of centuries and amidst all kinds 

 of physical changes, all the higher classes of animals 



* Pouchet " Sur 1'Heterogenie," Paris, 1859, 1 vol. in 8vo. 



