5 20 



THE ANIMAL PARASITES OF MAN 



known as 'Norway itch,' the scabies norvcgica of Hebra, 1852. 

 The afflicted man was covered with thick, creamy white, leathery 

 scales ; some of these scales measured over an inch in diameter and 

 ^0 in. thick. A constant shedding of scales went on, a handful 

 being gathered daily. They were found full of mites and eggs and 

 riddled with passages. Under treatment the mites were killed and 

 the skin became normal. Dr. Hessler made a calculation of the 

 number of eggs and mites, amounting to ova and shells 7,004,000, 

 mites in all stages 2,009,000. F. V. T.] 



The following forms may be transmitted from DOMESTIC ANIMALS 

 to MAN : 



(1) S. scabiei var. equi. Male, 0*2 to 0^23 mm. long, o l i6 to 0*17 mm. broad. 

 Female, 0-40 to 0*42 mm. long, o - 28 to 0*32 mm. broad. The horse is the normal host. 



(2) S. scabiei var. ovis. Male, 0-22 mm. long, o'i6 mm. broad. Females, 

 0*32 to 0*44 mm. long, 0*24 to 0*36 mm. broad. This mite lives on sheep, and passes 

 over to goats and human beings; it may also be artificially transferred to horses, 

 oxen and dogs. 1 



(3) S. scabiei var. capra. Male, 0x24 mm. long, 0*188 mm. broad. Female, 

 0*345 mm. long, 0^342 mm. broad. On goats, passing from them to horse, ox, sheep, 

 pig and man. On the latter, in contradistinction to the varieties (i) and (2), it pro- 

 duces a severe affection. 



(4) S. scabiei var. cameli. Frequently observed in man, chiefly in Africa. A 

 few cases have been observed in Europe ; the affection induced by it is severe. 



(5) S. scabiei var. auchenice. Male, 0-245 mm - l n g> 0*182 mm. broad. Female, 

 0*34 mm. long, 0*264 mm. broad. It lives on the llama, and may be transmitted 

 to man. 



(6) S. scabiei var. sut's. Male, 0-25 to 0*35 mm. long, 0*19 to 0-3 mm. broad. 

 Female, 0-4 to o'5 mm. long, 0-3 to 0*39 mm. broad. In the domestic pig and wild 

 boar ; occasionally also in man. The settlement, however, is usually of short 

 duration. 



(7) S. scabiei var. canis. Male, o'lg to 0^23 mm. long, 0-14 to o f i7 mm. broad. 

 Female, 0*29 to 0*38 mm. long, 0*23 to o'28 mm. broad. In the house-dog, and also, 

 not unusually, in human beings. 



(8) and (9) ,. scabiei var. vulpis and S. scabiei var. leonis of the fox and lion 

 have likewise been observed on man. 



These are all distinct species and should read as follows : S. cam's, Gerl. ; S. ovis, 

 Megn. ; S. egm, Gerl. ; S. dromedarii, Gerv. (cameli, Megn.) ; S. auchenice, Raill. ; 

 S. sin's, Gerl. : S. vulpis, Fiirst. ; S. leonis, Can. 



Sarcoptes minor, Ftirstenberg, 1861. 



Anus situated on the back, legs short, pedunculated ambulacra 

 broad ; living on cats (S. minor var. cati) and rabbits (S. minor var. 

 cuuiciili). In cats this mite usually lives in the cervical region, and 

 thence spreads to the ears and head ; it usually causes the death of 

 the infected animals; it is easily transferable from cat to cat, is 

 difficult to transmit to rabbits, but once settled on them can easily 



1 [This mite produces the so-called " black muzzle " of sheep. F. V. T.] 



