414 PARASITES OF ANIMALS 



rhynchus gigas. In the first book of this work I have given 

 my reasons for not regarding Welch's " encysted Echino- 

 rhynchus in man " as a genuine example of this curious genus of 

 entozoa. 



The external parasites of swine are not so numerous as might 

 be expected from the habits of their hosts. The most common 

 ectozoon is the hog louse (Hamatopinus suis). This disgusting 

 little insect is about J" in length. Almost equally common is 

 the hog mite. Though hitherto considered as a distinct species 

 (Sar copies suis, Gurlt), it is regarded by Megnin as a mere 

 variety of Sarcoptes scabiei. As Gerlach and others have 

 remarked, it is readily transmissible to man. The Sarcoptes 

 squammiferus, of Furstenburg, is only another name for this 

 variety of S. scabiei. Speaking of this scab-insect Megnin 

 says : " This parasite was first encountered by Spinola and 

 Gurlt, and afterwards by Muller." He then adds : " A 

 Ceylon wild boar died at the menagerie of the Museum of 

 Paris of a chronic affection of the skin which had transformed 

 its integument into a vast lichen." Lastly, as regards the 

 protozoal parasites I can only remark that the psorosperms 

 (spoken of as Rainey's corpuscles or as Miescher's utricles) are 

 often very abundant in the flesh of otherwise perfectly healthy 

 swine. Having dwelt upon the character of such organisms 

 in the first moiety of this work, I will only remark that the 

 full significance of these singular bodies yet remains to be 

 determined. Rainey's notion that they represented early stages 

 of cysticercal growth is altogether untenable. According to 

 Behrens, as quoted by Davaine, psorosperms are especially 

 abundant in the flesh of swine which have recovered from the 

 disease called mal rouge. On the subject generally, the writings 

 of Rivolta, Waldenburg, Eimer, and Siedamagrotsky are espe- 

 cially trustworthy. Full references to these and other authorities 

 are given in the synopsis of the 2nd edition of Davaine's well- 

 known treatise. 



BIBLIOGRAPHY (No. 54). (Anonymous), "On Parasitic Maladies, 

 especially Measles, of the Pig/' from ' Scottish Farmer and 

 Horticulturist/ in ' Edin. Vet. Rev./ p. 688, 1861. Ballard, E., 

 " On Diseased Meat, and what to observe in cases of suspected 

 Poisoning by Meat or Sausages (infected with Entozoa, &c.)/' 

 <Med. Times and Gaz./ Jan., 1864. Bowditch, H. ./., " Raw 

 Pork as an Aliment (without reference to the question of 

 Eiitozoa. T. S. C.)/' ' Boston Med. and Surg. Journ./ vol. Iv, 



