376 



THE ANIMAL PARASITES OF MAN 



dried fruits, &c., and have been occasionally observed in the 

 stools, urine, or pus of human beings, and also on their skin. 

 The so-called vanillismus is to be attributed to these species. 1 



[Tyroglyphus siro and T. farina are the same. They are 

 described under other names, such as A car us lactis, Linn. ; Acarus 

 favorum, Herm., &c. ; Acarus lactis in milk ; farina in flour, and 

 siro in cheese. 



It is to this 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. 



FIG. 240. Tyroglyphus farince, male 

 (enlarged). (After Berlese.) 



FIG. 241. Tyroglyphus longior, 

 Gerv. ( After Fum. and Robin.) 



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 thesame species. 

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

 dysenteric. No records have occurred since. It cannot be, as 

 Latreille supposed, the cheese-mite, for they have been eaten by 

 millions since, and it is strange no such case has occurred. F. V. T.] 



1 Layet, A., " Etude sur le vanillisme " (Rev. d'hyg. et de policesanit., 1883, v., p. 711)- 



