MICROBIAL DISEASES OF MAN AND DOMESTIC ANIMALS 879 



ENTEROHEPATITIS or TURKEYS 

 Entamceba meleagridis Smith, 1895 



Entero-hepatitis, or black-head, of turkeys is caused by Entamceba 

 meleagridis. The disease is widespread throughout North America. 

 It is a very fatal affection and on many farms it makes the raising of 

 turkeys a difficult problem. The disease is characterized by thick- 

 ening and ulceration of the caeca, and by extensive necrosis of the liver. 

 Entamceba meleagridis is a small amoeba measuring about Sfj. to ioju in 

 diameter. Turkeys probably become infected with this parasite by 

 swallowing its encysted forms; young turkeys may possibly become 

 infected from encysted amoebae, which adhere to the shells from which 

 they were hatched. 



There has been no efficient treatment devised for the disease, since 

 it is usually not noted until far advanced, but it can be avoided through 

 keeping healthy stock on land which has never been infected by drop- 

 pings from infected birds, and by carefully wiping eggs intended for 

 hatching with formalin. 



FLAGELLATA (Cohn emend. Biitschli) 



The herpeto monads and the trypanosomes are the most important of the para- 

 sitic flagellates. 



LEISHMANIA (Ross, 1903) 



The three parasites belonging to this genus which require mention are included 

 by some authorities in the genus Herpetomonas but the differences with respect to 

 habit of life justify the recognition of a distinct genus. Herpetomonads live in the 

 alimentary tract of various insects, for example, of the common blow fly and are 

 extracellular parasites. Their bodies in general are rigid. Leishmania is, on the 

 other hand, an intracellular parasite and in the flagellated phase of its develop- 

 ment its body is plastic and bends during locomotion. Three species are 

 recognized in association with three distinct types of disease in man. It is probable 

 that all of the Leishmaniases will be found, eventually, to be caused by a stage in the 

 life cycle of insect-borne herpetomonads. 



KALA AZAR 



Leishmania donovani Laveran and Mesnil, 1903 



This disease occurs in certain parts of Asia. It was first noted 

 in Assam, Northern India. 



