MICROBIAL DISEASES OF MAN AND ANIMALS. 68 1 



Trypanosoma equiperdum is most easily found by examining serum ob- 

 tained by puncturing these oedemas. 



SPOROZOA. 

 This class contains many very important pathogenic parasites. 



COCCIDIUM. 



Coccidia of various species are parasitic in the epithelial cells lining the 

 intestines of mice, horses, cattle, pigs, goats, and other animals. In Europe, 

 Coccidium cuniculi sometimes causes an enteritis of cattle; in East Africa, 

 a coccidium causes a serious disease of cattle. Other coccidia kill many 

 young pigeons, grouse, and chickens. Coccidia have been found in the intestines 

 and in the pleural cavities of man. 



COCCIDIOSIS OF RABBITS. 



The coccidium causing this disease is the best known of the coccidia 

 affecting mammals; it is called Coccidium cuniculi. 



This coccidium is parasitic within the epithelial cells of the intestine and within 

 liver cells. Adult, asexual forms measure from 20 fj. to 50^ in diameter and they produce 

 from 30 to 300 merozoites. The merozoites infect other epithelial cells or find their 

 way, by the bile passages, to the liver cells; they may again multiply asexually or they 

 may develop into male and female forms destined to multiply sexually. One of the 

 microgametes, produced by a microgametocyte, fertilizes a macrogamete and an oocyst 

 is developed. Within the oocyst a number of sporoblasts form, which contain two spores 

 each. The oocysts are excreted with the faeces; if they are ingested by a suitable host 

 the spores are set free, when the cyst reaches the intestine, and a new infection is com- 

 menced. 



Since the cells parasitized by the coccidia are destroyed, it is evident 

 that a severe infection may do a great deal of harm and interfere with the 

 functions of both intestine and liver. The disease may be limited by 

 making it impossible for uninfected animals to come in contact with the 

 droppings of infected stock. 



WHITE DIARRHCEA or CHICKS. 



The name is applied to a condition in young chicks, which is character- 

 ized by the passage of gummy, white faeces. It is not improbable that 

 this symptom may be produced by other causes; but one form of white 



