272 JOURNAL OF ECONOMIC ENTOM(^LOGY [Vol. 10 



control over the stock yards, in a number of important centers the es" 

 tabhshment proprietors own a controlUng interest in these yards and 

 hence much improvement can be brought about if their attention is 

 directed to the existence of insanitary conditions in such yards. This 

 appHes more especially to the larger establishments, nearly all of which 

 are under government inspection. 



In those plants which are under proper supervision an opportunity 

 is afforded for systematic efforts toward the immediate alleviation 

 and ultimate elimination of these conditions. A somewhat different 

 and much more serious set of conditions prevail at the small slaughter 

 houses not under inspection. In nearly all these no facilities are pro- 

 vided for the utilization of any of the offal or manufacture of any by- 

 products which results in the production of exceedingly insanitary 

 conditions instead of giving clean premises and a substantial financial 

 return. In some instances hogs are yarded around the uninspected 

 slaughter houses where they feed upon the blood and offal, and thus 

 are subjected to dangers of infection with tuberculosis and other dis- 

 eases, as well as internal parasites, to say nothing of the indescribable 

 fly-breeding conditions produced. The wallows made interfere with 

 drainage and the blood and remaining portions of entrails, bones, etc., 

 accumulate in the surface mud and sometimes render the entire pen 

 a prolific fly-breeding ground. In other instances the maggots and 

 bacteria are depended upon to dispose of the entrails and clean the 

 bones. Usually the flies emerging from their filthy environment have 

 ready access to the slaughter house, the interior of which is usually in 

 keeping with the outdoor conditions. Little or no effort is usually made 

 to prevent flies in countless numbers from swarming over the freshly 

 skinned animals, but some precautions, such as killing late in the even- 

 ing or the generation of smudges, are necessary to prevent the blowing 

 of the meat, which, nevertheless, frequently occurs. These crude 

 steps are taken not for sanitary reasons so much as to avoid loss from 

 trimmiing or the danger of the meat exhibiting to the prospective buyer 

 some gross evidence of the very obnoxious conditions under which it 

 was prepared. 



Species of Insects Concerned \ 



The insects which cause trouble about packing houses may be di- 

 vided into three groups: The Diptera — including house-flies, blow- 

 flies and others; the cockroaches, and ham and hide beetles. From 

 the point of view of the packer and the sanitarian, the house-fly and 

 various species of blow-flies are of by far the greatest importance. The 

 season of the activity of blow-flies is somewhat greater than that of 

 the house-fiv on account of the varied seasonal habits of the different 



