232 JOUKNAL OF THE DEPARTMENT OF AGRICULTURE. 



but we do not know how long- sncb bacteiia can remain in an animal 

 once it has been removed out of a lanf ziekte area if it does not die ; 

 nor do we know to what extent its faeces will scatter spores. If the 

 beast should die outside a lamziekte area, we do know, from the 

 Onderstepoort experiments, that its carcass is very likely to become 

 toxic, but we do not know enoug-h concernino^ environmental condi- 

 tions of putrefaction, and localization of pica, to know how likely it 

 is that such will propagate the disease. 



These are all points which have to be cleared up in the future. 

 Meanwhile we must admit that the disease can spread, and is steadily 

 spreading* to areas in whicli it was formerly unknown. Experience 

 shows that the scattering- of the causal organisms is a slow process, 

 but it is none the less a serious menace which must be brought under 

 control. 



At present there are many areas in which pica is prevalent, but 

 in which the disease is unknown. Such are the danger "grounds. 

 In Natal, for instance, the carcass material collected for experimental 

 purposes has so far proved non-toxic, although grathered from farms 

 on which craving- was very pronounced. Some of these areas may 

 possibly be safeguarded by a moister climate, and other conditions of 

 putrefaction about which we know little as yet. But there are also 

 areas in which we know that no safeg-uards exist and which are only 

 saved by the localized character of their infection ; as, for instance, 

 on two neighbouring- farms, with the same climate, on the same type 

 of soil, and belong-ing- to the same owner, who adopts the same pre- 

 cautions ag-ainst the disease in both places, but finds his mortality 

 hig-h on one and neglicrible on the other. Such differences are most 

 probablv due to a difference in soil infection and the absence of 

 mechanical carriers of spores from one area to the other. Once a 

 carcass on the clean farm becomes infected, however, the process of 

 multinlication of the toxicogenic saprophytes may proceed very 

 rapidly. Each animal that dies of lamziekte. or from anv other 

 cause, is then liable to become a breedings ground, and infection may 

 become so heavy as to drivp the unfortunate owner to abandon cattle 

 rearing altogether. 



In reg-ard to the measures for controlling- lamziekte it is 

 practically hopeless to attempt to eliminate the organism by any 

 other means than destroying- its food supply, i.e. by cleaning- the 

 farm of all carcass material. If this is done the remaining- soil 

 infection will slowly die down, and so long- as all dead animals are 

 disposed of as soon as discovered, the bacteria may possibly die out 

 altogether, and the danger from undetected small fragments of carrion 

 so disappear. 



The M\teetal oft of which the Toxtn is Manufactured. 



So mucli has been said on this matter under the two preceding- 

 headings thatjittle remains to be discussed. It is sufficient to 

 emphasize again that any dead animal whatsoever, from whatsoever 

 cause it died, can serve as substrate or material out of which the toxin 

 can be elaborated. 



The important constituent of the substrate is the protein or nitro- 

 genous matter, and all the tissues of the body are associated with 

 protein. Even bone contains just about as much nitrogenous organic 



