1 8 Annals Entomological Society of America [Vol. 111. 



female of Pcdicnloides ventricosiis, at a stage of her development 

 when these mites are most abundant in grain and straw, that is 

 to say they had not yet commenced to become gravid. After 

 making drawings of the ventral surface. Geber instead of turning 

 this same individual over and making a drawing of the reverse 

 or dorsal side took for this purpose wh^lt he presumed to be anoth- 

 er mite of the same species. The facts are that in all probability 

 the second mite w-as a male, as in speaking of the striking agree- 

 ment between the two individuals, he says "it remains to be 

 noted only that the indi\-iduals shown by figure 2 were \-ery 

 rare, only here and there were they to be found and they were 

 easily recognized by their peculiar form." In view of this it 

 would seem quite probable that the mite involved in the eruption 

 recorded by him might ha^•e been what we in America know as 

 Pedictiloides ventricosiis. 



In July 1882, Roller" records a case where 30 workmen in 

 Budapest were engaged in unloading sacks of barley coming from 

 Roumania and were seized within a half hour by an intense 

 itching, increasing in intensity during the several succeeding 

 days. Vesicles, the largest of which were the size of a millet 

 seed, appeared on inflamed bases on the neck, chest and other 

 portions of the bodies of these laborers. Koller states in this 

 connection that several years pre\'iously he had observed a simi- 

 lar malady contracted after unloading sacks of wheat from a boat. 



Prof. Howath found a mite in the wheat which completely 

 resembled that described by Robin, and several years prior to 

 this, similar obser\-ations had been made on the banks of the 

 Theiss, and in this case there was no other way to avoid the 

 trouble except to submerge the boat with its cargo. At the same 

 time that Koller observed this ease, trouble was observed at 

 Cologne with wheat coming from Russia. 



Flemming" in 1884 published the results of similar observa- 

 tions upon workmen in Klausenburg, who unloaded wheat 

 imi)ortcd from Russia and were suddenly seized with a skin 

 eru])tion. 



If we com])are these records from different parts of Europe 

 and in\-ol\ing other adjacent countries as well, we will notice 

 the similarity between these epidemics of a dermatitis and those 



6. Koller, G. Ein Getrcide-MilVic als Kr;inkhcitsene:;erin. .\nalvscd in 

 Biolo},^ CentralVii. t. IFI, 1SS4, page 127. 



7. F^lemming, J. Ucber eine Geschlcchtsrcife Form dor ala Tarsoneiiius 

 beschrielien Thiere, Zcitschr. f. Naturwissensch B. LVIl, 1S.S4, page 472, pi. 2. 



