364 Developmental History of Infusorial, Animal Life. 



chemistry, have never been disputed, and other observers, 

 following in his footsteps, have extended their researches.to the 

 organisms which arise in vegetable infusions ; and all, whether 

 partisans or opponents of the theory of spontaneous generation, 

 admit that the smallest possible quantity of atmospheric air is 

 sufficient, when brought into contact with a suitable infusion, 

 to produce in a short time such changes, that there appears an 

 incredible number of minute forms of animal life. The 

 character of the infusion most decidedly exerts an influence over 

 the ultimate results ; as for instance when any kindof albuminous 

 material is added to the saccharine fluid, the spores of a fungus, 

 Penicillkim glaucum, cover the surface in a few days ; the in- 

 fusions are also affected by the atmospheric conditions, whether 

 summer or winter, by locality, whether placed inside or out- 

 side the house, in town or in country. 



To sum up, and in a few words, after having carefully con- 

 sidered the arguments used by disputants on both sides of this 

 question, I believe I am perfectly right in saying that the balance 

 of experiment is certainly very much against the spontaneous 

 generation theorists ; but so much has been said and written 

 on this subject, that we might if space permitted, greatly extend 

 our remarks. There is, however, another point deserving of 

 notice, which appears naturally to follow an inquiry into the 

 source of living organisms, namely, the order of their successive 

 appearance in vegetable infusions. This point in the life 

 history of the infusoria has already occupied the attention of 

 many investigators : and one in particular I wish to direct atten- 

 tion to, — Mr. Sarnuelson, whose researches were carried on in 

 conjunction with Dr. Balbiaui of Paris, and confirmed by him. 

 As might have been expected of this gentleman, he starts by 

 asserting his utter disbelief in spontaneous generation, and 

 then goes on to tell us that when a carefully prepared infusion 

 of vegetable matter in distilled water is exposed to the air, the 

 Protozoa which first appear in it are Amceba : these in a few 

 days disappear, and are succeeded by ciliated infusoria, such 

 as Kol/pocla, Cyclidiiim glaucoma, and sometimes Vorticclla, and 

 these in their turn by what we have looked upon as higher 

 forms, as Oxytrichum, Euplotes, Kerona, etc., consequently 

 Mr. Sarnuelson thinks that Monads are but the larval condition 

 of the ciliated infusoria. He also noticed the constant oc- 

 currence of Monads belonging to the species Cvrcomonas 

 fusiform/is, or acuminata of Dujardin, etc., in pure distilled 

 water after a certain exposure to the air, and this without the 

 previous admixture of vegetable matter of any kind in the 

 water. The same results were obtained upon shaking rags, 

 from various and distant parts of the world, over the distilled 

 water ; other experiments were also tried, and in all cases in 



