THE BEGINNINGS OF LIFE. 313 



The positive evidence now existing on this subject, 

 however, which may be considered all the more reliable 

 because it has been partly built up and confirmed by the 

 panspermatists themselves, is of the following nature. 



It has been established by most careful observation 

 that in dry air or in a vacuum, organisms are capable of 

 withstanding a notably higher temperature than when 

 they are immersed in fluid. According to the direct 

 observations of M. Pasteur, the spores of certain fungi 

 belonging to the family Mucedine<e seem to possess this 

 tenacity of life to a very great extent ; but even these, 

 he says, though they still remain capable of germinating 

 after having been raised for a few minutes in dry air 

 or in vacuo to a temperature of 1 20 to 1 25C (248 

 257F), lose this power absolutely and entirely after an 

 exposure for half an hour, under similar conditions, to 

 a temperature varying from 127 to I3OC (260 

 266F). And the labours of the commission appointed 

 in 1860 by the Societe de Biologic (consisting of the 

 following members MM. Balbiani, Berthelot, Broca, 

 Brown-Se'quard, Dareste, Guillemin, and Ch. Robin) 

 to enquire into the subject, led them to the conclusion 

 that the lower animals which were the most tenacious l 

 of life the rotifers, the c sloths,' and the anguillules 

 of tufts of moss or lichen succumbed at even a much 



1 This extreme tenacity of life is perhaps due in part to the chitinous- 

 integument with which all these animals are provided. It is certain that 

 very many of the lower forms, not so protected, are destroyed more 

 easily by the influence of heat both in the presence and in .the absence of 

 moisture. 



