THE ANIMAL PARASITES OF MAN 



Tyroglyphus longior, Gervais, 1844. 



White or yellowish, with two black spots on the abdomen. 

 Male 0*55 mm. in length, 0*28 mm. in breadth ; penis bent. 

 Female 0*61 mm. in length and 0*28 mm. in breadth. 



T. siro and T. longior live on dry cheese, in flour, on dried fruits, 

 etc., and have been occasionally observed in the stools, urine, or pus 

 of human beings, and also on their skin. The so-called va'nillismus 

 is to be attributed to these species. 



[T. siro and T.farince of Schrank (non Geer) are the same. They 

 are described under other names, such as Acarus lactis, Linn. ; 

 A. favorurn, Herm., etc. ; A. lactis in milk, farince in flour, and siro 

 in cheese; and as A. dysenteric?, Linnaeus (" Syst. Nat.," ed. 12, 

 pp. 1024-1767).] 



FIG. 363. Tyroglyphus farina : male. 

 Enlarged. (After Berlese.) 



FlG. 364. Tyroglyf>htis' longior, 

 Gerv. (After Fum. and Robin.) 



It is to these species that a case of dysentery was referred. 

 Rolander, who studied under Linnaeus, was attacked by what was 

 called dysentery. The complaint soon gave way to treatment, 

 but eight days after it returned, soon disappeared, but again 

 came a third time. All the time Rolander had been living like 

 the other inmates of the house, who all escaped. Linnaeus, aware 

 that Bartholemy had attributed dysentery to insects which he 

 said he had seen, advised his student to examine his stool. The 

 result was that innumerable mites were found to be present. Their 

 presence was easily accounted for by the fact that they were found 

 in numbers in a cup made of juniper wood from which the student 

 alone drank of a night, and they were found to be of the same species. 

 What this species is we do not know. Linnaeus called it Acarus 

 dysenteric?, but it was the same as his Acarus siro. No records have 



