RESPIRATION IN SOUTHERN WHALES 



395 



A third sample of blood was taken as cleanly as is possible on board a factory ship 

 from a pig at the moment of being killed (25. i. 33) and frozen to —10° C. for 5 days. 

 The bottle was then allowed to stand for 3 days unopened at room temperature. At the 

 end of this time, the blood was seen to contain great numbers of the X organisms. No 

 other infection was apparent. The small organisms were seen to be attacking the 

 erythrocytes, 10 or 12 organisms to each corpuscle, a feature of their activity which 

 had been noted in fresh adult and foetal blood when there was little oxygen present. 

 A number of experiments were performed in the burette. The nitrogen content of the 

 blood was i • 1 1 vol. per cent. The following amounts of nitrogen were removed from the 

 blood in six separate experiments : 



* With octylic alcohol. 



So far as the crude technique can show, this blood alone of the samples of pig's blood 

 became infected with X organisms and behaved exactly like whale blood. Whether 

 the infection occurred m vivo or in vitro it is impossible to say ; the former is possible 

 since the pig-sty was close to a deck running with whale's blood. 



NATURE OF X ORGANISMS 



The behaviour of the organisms which were found in all samples of Blue and Fin 

 whale blood, adult and foetal, suggests that they may be a kind of bacterium. Their 

 presence in foetal blood militates against their being any known species of bacterium 

 since, so far as is known, the very few bacteria which are able to penetrate the foetal 

 membrane are pathogenic. 



The experiments with cultures and pig's blood suggest that the nitrogen removal or 

 fixation, as perhaps it may be called, is performed by the X organisms. The appropriate- 

 ness of this fixation in dealing with the problem of caisson sickness has been suggested, 

 but at the same time the possibility that the bacteria are present in the blood as a result 

 of post-mortem infection has not been overlooked. The presence of the bacteria in such 

 huge numbers in the freshest of whales and particularly in their foetuses is strongly in 

 favour of their being present in the blood of living whales. However, these conclusions 

 are offered with some degree of diffidence, since it is unheard of that even a benignant 

 organism should be found in such numbers in the blood of a mammal. 



The X organisms' resistance to freezing was indicated in the last experiment with 

 pig's blood. Subsequently a number of samples of adult and foetal whale blood, which 



