314 READINGS IN BIOLOGICAL SCIENCE 



same locality, 105 out of 523 cattle, or 20 per cent, being infested, it was 

 determined that about 1,500 cattle, of which the 523 were a part, had been 

 fed during the winter and spring in the yards of a cottonseed oil mill. These 

 animals were later marketed at various live-stock centers and data were 

 obtained on the 523 animals already referred to. The remaining animals 

 were not traced to the point of slaughter. 



The investigation made at the yards of the mill disclosed that the regular 

 water supply for the cattle was taken from a river 75 yards below a sewer 

 outlet. The river was wide and shallow, had a sluggish current, and the 

 banks, which formed a portion of tract of land designed for a public park, 

 were strewn with human feces. The investigation disclosed further that 

 the cottonseed hulls used for feeding the cattle were stored in a building 

 where tramps commonly slept during the feeding season. Evidence was ob- 

 tained which indicated that the cottonseed hulls had become more or less 

 contaminated with human excreta, the hull house being used evidently 

 by the tramps and mill employees as a place for defecation, especially dur- 

 ing very cold weather. An inspection of the 3 outhouse toilets intended 

 for the use of the mill employees showed that the structures were of poor 

 design, the excreta falling directly on the ground or in boxes set on the 

 ground level. As many of the mill employees using these outhouses were 

 transients, it was estimated that about 200 persons used the three poorly 

 constructed and unsanitary outhouses during the cattle feeding season. 

 At the lower end of the feed yards there was a stagnant pool which drained 

 a watershed that included a portion of the town and cottonseed oil mill 

 with its three primitive outhouses. The cattle were occasionally forced to 

 drink from this stagnant pool as a result of frozen pipes which shut off the 

 regular water supply. The 1,500 cattle fed at the yards were therefore ex- 

 posed to the following sources of infection with tapeworm: (i) The out- 

 houses which drained into the stagnant pool; (2) the regular water supply 

 from the sewage-laden river; (3) the cottonseed hulls, which were more 

 or less subject to contamination, and (4) a portion of the town's waste 

 which drained into the stagnant pool. That fully 20 per cent, of the cattle 

 that were fed under these unsanitary conditions became infected, as shown 

 by the data obtained, is not surprising considering the four possible 

 sources of infection. 



Two recent outbreaks of cysticercosis in cattle, investigated by the Bu- 

 reau of Animal Industry, showed conclusively the important role of a single 

 human tapeworm carrier as a spreader of this parasitic infestation to bo- 

 vines. The facts in these cases are as follows: 



Following the receipt of information that 166 out of 252 cattle carcasses 

 were retained in an officially inspected establishment at Fort Worth, Texas, 

 because of infestation with tapeworm cysts, an investigation was made 

 of the premises where these cattle had been fattened for market. It was de- 

 termined that the bovines in question were kept in a feed lot to which feed 



