December, '21] scientific notes 509 



room for placing in the materials and taking out the bait. The edge 

 of the door were felted to prevent leakage. No paddles or other ob- 

 structions were placed inside the box; the falling of the materials from 

 one comer to another as the box revolved thoroughly m.ixed the bait. 



It was necessary to use a 3K" pulley on the engine to get sufificiently 

 low gear to turn the box about 36 revolutions per minute, which was 

 foimd to be the maximimi speed for best results. A one and one-half 

 horse power gas engine developed sufficient power to operate the mixer. 

 Two men operated it to its fullest capacity. 



The m,achine handled 100 pounds of bran at a time. The bran and 

 poison were placed in the box and mixed for about two minutes. The 

 syrup, ground oranges, or lemons, and water, mixed together, were then 

 added and mixed for from three to four minutes. The fact that there 

 were no paddles or other obstructions in the box made the removal of 

 the bait a simple matter. The bait was shoveled directly from the 

 machine into sacks. This feature proved an advantage over a barrel- 

 shaped mixer which required stationary- paddles to thoroughly mix 

 the bait. 



Scientific Notes 



Effect of Feeding Paradichlorobenzene-Treated Feed to Poultry. Last summer, 

 com in the Agronomy Seed Laboratories at Purdue University, was treated with 

 para-di-chloro-benzene to eliminate if possible and to prevent further infestation by 

 the angoumois grain-moth. Subsequently Prof. F. E. Robbins of the Agronomy 

 Department used some of this corn for feeding poultry, resulting in tainting the 

 flesh of the chickens to such an extent as to make it distasteful and inedible. Similar- 

 ly eggs laid by hens fed this treated corn were equally distasteful and inedible. It 

 has been previously noted that the eggs laid by hens fumigated with nitrobenzene 

 for the control of lice and mites are spoiled for food. 



J.J. Davis 

 Oct. 31, 1921, Lafayette, Ind. 



Notes on the Nest and the Population of a Colony of Vespa diabolica. Prompted 



by a ciu-iosity to learn something of the population of wasps' nests, I recently captured 

 among others two colonies of Vespa diabolica. As is well known these build a nest 

 not unlike that of various species of Polistes; but locate it in the ground instead of 

 in some tree or shrub. 



One of the nests was taken on September 26. The entrance on the surface of the 

 ground was about an inch in diameter. It was inlaid with pieces of gravel that were 

 held in place by a paper lining. By pouring a small quantity of carbon disulfide 

 into the entrance the wasps were readily pacified, whereupon the nest with all the 

 inhabitants was easily removed. The nest consists of six stories, and the base is 

 about ten and a half inches in diameter. 



