212] 



The Classification of Lower Organisms 



The name Haemosporidia, commonly applied to this order, appears to belong by 

 priority to the preceding. 



Schaudinn (1903) was disposed to connect this order with the trypanosomes, while 

 connecting the coccidians with Bodo and Cryptobia. This view has been entertained 

 by Liihe (inMense, 1906), Woodcock (1909), and Leger (1910). In spite of authority 

 thus good, it appears far-fetched. The Gymnosporidiida are of the same general na- 

 ture as the Aggregatida, Adeleida, and Haemogregarinida. 



Fig. 42. — a-m. Life cycle of Plasmodium compiled from various sources: a, infec- 

 tion of an erythrocyte by a sporozoite; b-e, trophozoites, plasmotomy, and mero- 

 zoites; f, spermatocyte; g, oocyte; h, production of sperms; i, fertilization; j, k, pro- 

 duction of sporozoites in cells of the gut epithelium of the mosquito; 1, sporozoites; 

 m sporozoites entering the salivary gland of the mosquito, n-q. Stages of division 

 of cells of Babesia bigemina in erythrocytes of cattle x 2,000 after Dennis (1930). 



The Gymnosporidiida are organized, somewhat arbitrarily, as three families. 



Family 1. Halteridiida [Halteridiidae]Hartmann and Jollos 1910. Family Leu- 

 cocytozoidae Hartmann and Jollos. Family Hacmoproteidae Doflcin. Hacmoproteus 

 Kruse {Haltcridium Labbc) occurs in reptiles and birds. Vegetative growth and re- 

 production occur in tissue cells. Some of the merozoites infect erythrocytes, and are 

 believed to become gametocytes, and to develop no further unless swallowed by some 

 blood-sucking arthropod. In the best known example, H. Columbae of pigeons 



