PARASITES OP ANIMALS. 61 



Dochmius duodenalis Leuckart. Small intestine ; Italy, 

 much more common in Egypt, causing very serious disease. 



ACARINA. 



Pentastoma dentimlatum Rud. (Probably the young of P. 



tcenioides of the dog.) In cysts on the liver, etc. ; not very 



rare. 

 P. comtrictum Siebold. Liver and lungs ; common in Egypt. 



PROTOZOA. 



Paramecium coli Malmstein. Colon, excreta. 

 Cercomonas intesiinalis Lambl. ((7. ^ommisDavaine). Intes- 

 tine ; from a cholera patient. 

 Variety B. From a typhoid fever patient. 

 C. urinarius Hassal. In urine. 

 C. saltans Ehrenberg. 



Trichomonas vaginalis Donne". Vagina, in mucus. 

 PsorospermSj (perhaps the eggs of Distoma). 



In addition to the preceding species of true parasites, 

 various kinds of insect larvae have been known to live for a 

 time in the human stomach and intestine, from which they 

 have been discharged either by vomiting or purging. 



Among the most common larvae that may thus live in the 

 human body are those of the various species of meat-flies, blue- 

 bottle-flies, blow-flies, or flesh-flies (see page 101), and those 

 of the house-fly. Several species of the genus Homalomyia 

 have also been known to occur in this way, the eggs or larvae 

 having been swallowed with fruit, and more especially in de- 

 cayed fruit, in which they naturally live.* Such larvae often 

 cause considerable irritation of the intestine, and diarrhoea, 

 but as their life in the larval state is very short, they must 

 soon pass from the intestine or perish in it. 



INTERNAL PARASITES OF THE DOG. 



CESTODES. 



Tcenia echinococcus Siebold. Intestine, many together ; larvae 

 in sheep, cattle, and man ; common. 



*These insects are well described by Mr. B. D. Walsh in the American En- 

 tomologist, vol. II, page 137, 1870. 



