316 



Profs. Percy Frankland and Marshall Ward. 



14. The results obtained with the anthrax spores in the tin- 

 sterilised waters were not influenced by whether these waters were 

 preserved in darkness or exposed to diffused daylight. Exposed to 

 direct sunshine, however, the anthrax spores were rapidly destroyed, 

 not more rapidly, however, than in the sterilised waters under the 

 same exposure (pp. 204 — 213). 



15. In experiments made in order to test the nature of the conflict 

 between anthrax and particular forms of water bacteria, the Bacillus 

 jluorescens liquefaciens (Fliigge) was employed in pure cultivation 

 along with anthrax in approximately equal proportions. The results, 

 however, show that this saprophyte, at any rate, has not the power of 

 rapidly destroying the anthrax spores ; indeed, there was no evidence 

 that either it, or its products, act prejudicially on anthrax spores at 

 all (pp. 290—298). 



16. In connexion with the antagonistic interests of the anthrax on 

 the one hand and the several kinds of water organisms on the other, 

 it is worthy of note that in one experiment in which anthrax spores 

 were introduced into unsterilised Thames water exposed freely to 

 daylight, and in which in addition to water bacteria there was also 

 present a quantity of small algse, the anthrax spores survived the 

 conflict with these competing forms for upwards of seven months, 

 although enormously reduced in numbers and much impaired in 

 virulence (pp. 278, 283). 



17. To summarise our results with anthrax spores in one sentence, 

 we may state generally that there is one natural agency at least 

 which is capable of destroying them in surface waters to which they 

 may have gained access, viz., the action of direct sunshine on the 

 organism. Whether the activity of water bacteria may be added as 

 a second bactericidal agent is not definitely determined, but, in any 

 case, of these two influences the sunshine is by far the more rapid 

 and the more potent, though its sphere may be much more re- 

 stricted. 



18. Behaviour of Anthrax Bacilli. — As regards the behaviour of 

 anthrax bacilli free from spores, it should be pointed out that we 

 have only experimented with such spore-free bacilli obtained from 

 artificial cultures, and not with those derived directly from the 

 organs of an animal dead of anthrax. We have in many cases found 

 that the bacilli obtained from artificial cultures behave in essentially 

 the same way when introduced into water as do the spores under the 

 same circumstances, and apparently for the reason that the bacilli 

 introduced rapidly produce spores in the water, and the subsequent 

 phenomena thus become identical with those which we have already 

 discussed above (pp. 260, 272, 278). 



19. Some of the evidence points to the possibility of the multiplica- 

 tion of the bacilli in waters containing more than the usual amount 



