286 THE BEGINNINGS OF LIFE. 



What, then, are we to say to the assumptions of 

 M. Pasteur, that certain rounded structureless particles 

 are indeed c organized corpuscles ' or the c germs ' about 

 which the panspermatists talk so much ? To say nothing 

 of the important modifications which M. Pasteur has 

 felt himself compelled to make in reference to the old 

 doctrines of Spallanzani *, we find that all which he has 

 yet been able to establish as a matter of certainty, and 

 as a result of actual observation, is, that the atmo- 

 sphere of certain regions does contain a very appreci- 

 able quantity of extremely minute more or less spher- 

 oidal and transparent particles, which he (M. Pasteur) 

 assumes to be the much-talked-of germs. But no 

 direct proof of this has ever been adduced. Let us 

 not deceive ourselves, either, as to the amount of 

 similarity between the germs in question and the 

 particles actually found it is of a negative rather 

 than of a positive description. M. Pasteur is not able 

 to say that the spore of a fungus has such and such 

 structural peculiarities, and that the bodies which he 

 has found present similar definite characters. Such 

 evidence would be cogent in direct proportion to the 

 number and variety of details of structure in respect of 

 which the two bodies were found to correspond. Here, 

 however, the case is quite different, and the value to 

 be set upon the similarity presented undergoes a corre- 

 sponding decrease. The spores of some of the micro- 

 scopic fungi, as M. Pasteur says, are mere little spheri- 

 1 See pp. 2/2 and 274. 



