The Cause and Preven'Tion of Lamziekte. 229 



that it is not produced by normal putrefaction occasioned by the 

 ordinary widely distributed bacteria ; the question naturally arose : 

 How does a carcass become infected under natural conditions? 



Experiments were carried out to answer this question. A cow 

 which had died on the veld from another disease was allowed to 

 decompose with an intact skin. Putrefaction set in rapidly. After 

 twenty hours the spleen was removed and drenched to a tollie, which 

 duly developed lamziekte and died. Although the dose of putrefying 

 material was fairly high, the period of twenty hours represents a rate 

 of toxin production which is phenomenally rapid. As a rule a few 

 days elapse before carcass material is toxic. The interesting point 

 in this experiment, liowever, is just the very fact that the brevity of 

 the period practically excludes infection of the spleen from the out- 

 side througl) the intact skin, and throws the weiglit of evidence in 

 favour of infection from the intestinal contents of the carcass imme- 

 diately after death. The intestinal contents themselves could, of 

 course, easily be infected by the ingestion of infective but non-toxic 

 juaterial, without producing death. Partially' bleached bones, from 

 which the toxicity has disappeared but which still harbour spores of 

 the toxicogenic saprophyte, are very common on the veld, and such 

 material would infect the intestine without necessarily doing any 

 liarm to the animal. Another source of harmless infection of the 

 intestine may be particles of infected soil, and grass infected by spore- 

 laden dust from the site of an old cadaver. This experiment indicates 

 an infection from the ituide of the carcass. 



Another interesting experiment was carried out with a ftill-time 

 foetus from a cow which died on the eve of calving. Since there is 

 no direct intercourse between the blood of tlie mother and the blood 

 of the foetus, it may be accepted that the unborn calf was not infected 

 with bacteria from the cow. This calf was at once removed and 

 exposed to putrefaction on the veld. Material subsequently collected 

 from it, and drenched to a tollie. promptly produced lamziekte. 

 This calf, then, represents a case of infection from the outride. 



Control experiments were carried out in fenced paddocks at 

 Onderstepoort, i.e. a non-pica area free from lamziekte. Post- 

 mortem-room carcasses, to which no suspicion of lamziekte infection 

 was attached, were exposed on the local veld. Putrefaction set in as 

 usual, but the carcass material proved non-toxic. Certain animals 

 were then drenched with toxic material sent from Armoedsvlakte, 

 contracted lamziekte, and died. Ou putrefaction these carcasses now 

 proved toxic, thus indicating again the infection of the cadaver 

 through the intestine. The disease could readily be maintained in 

 the Onderstepoort paddock by carrying the infection through 

 successive animals, poisoning each one by drenching the carcass 

 material of its predecessor in woe. This was done through seven 

 generations, and then abandoned as a conclusive experiment. A 

 tendency, however, was noted towards non-toxic putrefaction in some 

 of the animals (negative duplicate experiments) drenched with experi- 

 mentally produced carcass materinl, thus suo-o-esting that tlie local 

 conditions (climate, competitive putrefactive flora, etc.) were less 

 favourable to toxin prodtiction than at Armoedsvlakte. On the other 

 hand, a non-infected carcass from the post mortem table, exposed in 

 the vicinity of the toxic carcasses of the experimental paddock, 



