Royal Microscopical Societij. 103 



But this protection, whatever it may be, is only for a time ; for 

 all authors concur that if the boiling or heating be continued long 

 enough, with proper precautions, all living things, germs as well as 

 adults, are destroyed. This is attested by Wyman, Cohn, B. 

 Sanderson, Eoberts, Pasteur, Huizinga, and others. Only a long 

 series of carefully-conducted and controlled experiments on forms 

 thoroughly worked out, can enable us to decide what length of time 

 is absolutely fatal to the sporule as well as the adult. At present 

 we believe that any results are vitiated by taking it for granted 

 that they must be destroyed at an arbitrary temperature endured 

 for an arbitrary time. Who is to say, without competent experiment 

 on the form (whose life history should be known), that more pro- 

 longed heating would not have yielded other results ? 



But this is only a negative error. A much more serious one, 

 we believe, has been introduced, or at least endorsed by Dr. Bastian, 

 when he assumes that the prolonged heating, or high temperatures 

 we ask for, must destroy the organizahle constitution of the albu- 

 minous matters which were spontaneously to form into bacteria. 

 That anything is or can be " organizable " in any sense except as 

 being capable of assimilation as pabulum is not even ex hypotheci ; 

 it is simply and entirely petitio principii; and we know as a 

 matter of fact that these substances, after being exposed to heat 

 enough to destroy living organisms, are nevertheless quite fit to act 

 as pabulum to other organisms, and are thus " organizable " in the 

 only knoivn mode in which any matter ever becomes living. 



Our researches show conclusively (we hold) that the assumption 

 that the germs of putrefactive organisms must perish in the same 

 conditions that destroy the parents, is erroneous. We have not 

 shown this of bacteria, it is true — the germs may be so minute that 

 our present optical appliances wholly fail to detect them — indeed, 

 the facts shown by us in relation to the monad we describe in the 

 earlier part of this paper * strongly support this. But it must be 

 remembered that the monads we describe are as much putrefactive 

 infusoria as the bacteria, and with as great a title to be called 

 " spontaneous " as they have. Scientifically we can see no reason 

 why the bacteria should be held to be more Ukely to grow sponta- 

 neously, than any other of the less minute forms whose hfe history 

 our present appliances enable us to work out. We venture to think 

 it more philosophical to work by experiment doivn to the bacteria, 

 hoping that by an accumulation of facts concerning these minute 

 forms, and probably — as we may anticipate — improved optical 

 appliances, to deal with the development of bacteria as we deal now 

 with the development of creatures more amenable to our knowledge 

 and our instruments. 



* ' M.M.J.,' Feb. 187-1, p. 71. 



VOL. XI. I 



