86 Dr. J. Wyman — Experiments on Infusoria. 



sisting of Monads and Vibrios, was found in xxxiv and xxxv, 

 but none in tlie others. 



The result of the experiments here described is, that the boiled 

 solutions of organic matter tnade use of exposed only to air which 

 has passed through tubes heated to redness, or enclosed with air in her- 

 metically sealed vessels and exposed to boiling water, became the secU 

 of infusorial life. 



The experiments wbicb have been described throw but little 

 light on the immediate source from which the organisms in 

 question have been derived. Those who reject the doctrine of 

 spontaneous generation in any of the forms in which it has been 

 brought forward, will ascribe them to spores contained either in 

 the air enclosed in the flask, or in the materials of the solution. 

 In support of this view it may be asserted, that it has been 

 proved by the microscopical investigations of Quatrefages, 

 Robin, Pouchet, Pasteur and others, that the air contains 

 various kinds of organic matter, consisting of minute fragments 

 of dead animals and plants, also the spores of cryptogamous 

 plants, and certain other forms, the appearance of which, us 

 Quatrefages says, suggests that they are eggs. ^ We have made 

 some examinations of our own on this subject, but it would be 

 unnecessary to give the results in detail. We will simply state, 

 that we have carefully examined the dust deposited in attics, 

 also that floating in the air collected on plates of glass covered 

 with glycerine, and have found in such dust, in addition to the 

 debris of animal and vegetable tissues, which last were by far 

 in the greatest abundance, the spores of Cryptogams, some 

 closely resembling those oi Confervoid plants, and with them, 

 but much less frequently, what appeared to be the eggs of some 

 of the invertebrate animals, though we were unable to identify 

 them with those of any particular species. We have also found 

 grains of starch in both kinds of dust examined, to the presence 

 of which Pouchet was the first to call attention. When com- 

 pared with the whole quantity of dust examined, or even w't.i 

 the whole quantity of organic matter, both eggs and spore« i^ -■^' 

 be said to be of: tutq occurrence. W^e have not in any in- 

 detected dried animalcules which were resuscitated by niu 

 and when the dust has been macerated in water none hu 

 peared until several days afterwards, until after a lapse of ' 

 when they would ordinarily appear in any organic solution. 



Those who advocate the'theory of spontaneous generation, on 

 the other hand, will doubtless find, in the experiments here re- 

 corded, evidence in support of their views. While they admit 

 that spores and minute eggs are disseminated through the air, 

 they assert that no spores or eggs of any kind have been acta- 



« See an abstract of Pasteur's research 



