ZOOLOGY. 303 



meets with the hot steam, and the spores or organisms contained in it 

 are killed ; while those which enter the tube later move more slowly, 

 and are deposited on the moist walls of it without entering the body 

 of the flask. 



To verify these and other researches of M. Pasteur, Prof. Jeffries 

 Wynian, of Cambridge, has recently made a series of experiments to 

 test the question of the formation of minute living organisms in solu- 

 tions of organic matter which had been boiled and exposed, in her- 

 metically sealed vessels, to air which had passed through iron tubes 

 heated to redness. Thirty-seven experiments were tried, and of 

 these thirty-three were made at the ordinary pressure of the atmos- 

 phere, and all but five supplied with air through heated tubes. The 

 solutions were boiled from fifteen minutes to two hours before being 

 sealed, and infusoria appeared in all but four. The first indication of 

 them was a film, which formed on the surface of the solution, some- 

 times on the second day, generally during the first week, and occa- 

 sionally not until the nineteenth day from the commencement of the 

 experiment. The solutions consisted of mixtures of sugar and starch, 

 with some albuminous matter, of the juice of beef sometimes filtered, 

 and in other instances containing muscular fibre and vegetable sub- 

 stances. Five experiments were tried in flasks hermetically sealed at 

 the beginning, and then immersed in boiling water, in all of which 

 infusoria were formed. 



Four experiments were made with sealed flasks in a Papin's di- 

 gester, two of them under a pressure of two, and two under five 

 atmospheres. Infusoria were found in one of each. 



The organisms consisted of Vibrio, Bacterium, Torula, minute 

 Algas, also small, round, or oval bodies, moving with vibrating cilia. 



In conclusion, Prof. Wyman says : My experiments 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 investi- 

 gations 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 cryptoga- 

 mous plants, and certain other forms, the appearance of which, as 

 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 of 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 compared with 



