76 



DE. BASTIAN ON THE 



such matter may set up to the survival of the organisms, when 

 the above-named results may have been due to the survival of mere 

 chemical ferments or ' particles ' in such desiccated media. This 

 objection I pointed out in 1872 *, and it is one which must be met 

 before conclusive experiments can be made. Eortunately the 

 means for complying with this necessity are now within the reach 

 of all skilled experimentersf. This kind of differentiation requires 

 to be made especially by those who announce positive results. 

 It would be a matter of less urgency wherever accurate experi- 

 ments show an inability to resist desiccation, or to resist this 

 process j)lus the brief influence of boiling water. 



Before referring to a few inquiries w^hich I have myself made in 

 these new directions, it seems desirable to say a few words con- 

 cerning one other attempt to raise the standard of vital resistance 

 to heat for the germs of some organisms, as this particular evi- 

 dence has been frequently mentioned during the last year — in 

 fact, ever since Prof. Tyndall's contradictory experiments had 

 in some way to be explained. Nothing better shows the pau- 

 city of any thing like exact knowledge concerning the ability of 

 living matter to withstand a temperature of 212° F. and upwards, 

 together with the strongly felt desire of the panspermatists to 

 find it, than the altogether undue importance which has of 

 late been attached to this evidence, which was brought forward 

 nearly four years ago by the Eev. Mr. Dallinger and Dr. 

 Drysdale. 



These gentlemen are now well known as the authors of some 

 very elaborate and meritorious investigations on the life-history 

 of certain flagellate monads. In addition to reproduction by the 

 well-known process of multiple fission, they have described two 

 kinds of germs, one minute, but easily visible, and the other 

 so minute as to be quite indistinguishable individually, even by 

 the highest powers of the microscope. Some observations have 

 been made as to the eff'ects of difierent temperatures upon the 

 parent forms and upon these reproductive units. The manner in 

 which this investigation was conducted is thus described by the 

 authors J: — "An ordinary slide containing adult forms and sporiiles 

 covered in the ordinary way was allowed to evaporate slowly in 



* ' The Beginnings of Life,' vol. ii. p. 4. 

 t Brit. Med. Journ., Feb. 13, 1875, p. 201. 

 I Monthly Microsc. Journ., Aug. 1873, p. 57. 



