282 HANDBOOK OF PROTOZOOLOGY 



Hepatozoon muris (Balfour) (Fig. 119, ^). In various species 

 of the rat, Rattus. Several specific names were proposed for 

 the forms based upon the difference in host, locality, and effect 

 upon the hosts, but they are so indistinctly defined that the 

 specific separation is impossible. 



The invertebrate host is the mite. The schizogony occurs 

 in the liver of the rat. Young gametocytes invade the mono- 

 nuclear leucocytes and appear as haemogregarines. When the 

 blood is taken up by the mite, Laelaps echidninus, the two 

 gametes unite to form a vermicular body which penetrates 

 the gut-epithelium and reaches the peri-intestinal tissue and 

 grows. Becoming surrounded by a cyst-membrane, the cyst 

 contents break up into a number of sporoblasts and then into 

 spores, each of which contains a number of sporozoites. When 

 a rat devours the infected mites, it becomes infected. 



Genus Karyolysus Labbe. The schizogony occurs in the 

 endothelial cells of a vertebrate host (reptiles). Some mero- 

 zoites which are in reality young gametocytes enter the ery- 

 throcytes where they remain without further changes. When 

 a mite sucks the infected blood, gametogony and fertilization 

 takes place, producing zygotes which develop in the epithelial 

 cells and become the oocysts. In the latter a number of sporo- 

 blasts are formed and these are capable of vermicular move- 

 ment and make their way into the ovum, where each transforms 

 itself into a spore and develops a number of sporozoites. 



Karyolysus lacertarum (Danilewsky) (Fig. 117, g). In the 

 lizard, Lacerta muralis. Transmission by the mite, Liponyssus 

 saiirarum. 



References 



Calkins, G. N. 1926 The biology of the Protozoa. Phila- 

 delphia. 



DoFLEiN, F. AND E. Reichenow. 1929 Lehrbuch der Pro- 

 tozoenkunde. Jena. 



Labbe, A. 1899 Sporozoa. Das Tiereich. 5 L. 



Wasielewski, V. 1896 Sporozoenkunde. Jena. 



Wenyon, C. M. 1926 Protozoology. Vols. 1 and 2. London. 



Andrews, J. M. 1926 Coccidiosis in mammals. Amer. Jour. 

 Hyg., Vol. 6 



