THE BEGINNINGS OF IIFE. 335 



more likely that they had been newly evolved, by reason 

 of changes taking place in the blood after death, in or 

 near the situation in which they were found. It would 

 be impossible otherwise to account for their distribution 

 throughout the brain at a time when the circulation 

 had ceased 1. This organ is so far, comparatively, from 

 any mucous surface, that even if germs had been able 

 to make their way into the blood-vessels ramifying on 

 their surface (which is in itself altogether a gratuitous 

 supposition), it would be impossible for us to imagine 

 that, in such a short space of time, they could have 

 been able to penetrate into the innermost parts of the 

 brain. Their unceasing movements are extremely slow 

 in reality- and more than this, they are never con- 

 tinuously progressive. They consist either of slow 

 oscillations, or else of short darting movements hither 

 and thither, in which the same ground is frequently 

 retraced. And again, if Bacteria in their adult or in 

 their rudimentary state could make their way from the 

 atmosphere through the superficial layers of the mucous 

 membrane so as to penetrate the vessels, why, if it is 

 to be assumed that they do this after the death of an 

 individual, does not the same thing occur during his 

 life, more especially when the mucous membrane of 



novo in the blood, rather than that they had-been developed from germs 

 which had gained access to the blood from without. 



^ In all probability, if examination had been made, they would have 

 been found disseminated throughout all other parts of the body, just as 

 they were actually found in different parts of the brain. (See Appendix E, 

 p. cl, note I.) 



