66 GENERAL ORGANIZATION OF THE PROTOZOA 



Many species: In man, B. hominis, Manson, the disputed cause of Rocky 

 Mountain Spotted Fever; in cattle, B. bovis, Babes, 1888, and B. bigemina, 

 Smith and Kilbourne, 1893, and B. parvum, Theiler, 1904; in sheep, B. ovis, 

 Babes, 1892; in horses, asses, and mules, B. equi, Laveran, 1901; and in 

 dogs, B. canis, Piana and Galli- Valeric, 1895. 



Some genera of questionable taxonomic value are referred to this suborder. 

 Among them Polychromophilus, Dionisi, 1900, and Achromaticus, Dionisi, 

 1900, from the blood of bats of the genera Vespertilio and Vesperugo, must be 

 temporarily placed. The former is characterized by the presence of pigment 

 similar to that of Plasmodium, while in the latter such pigment is absent. 



Suborder B. HEMOSPOREA, Minchin, 1903. Intracellular blood parasites usually 

 called Hemogregarines, which become free in the blood. Alternation of hosts 

 in some cases, but apparently not in all. Parasites mainly in cold-blooded 

 animals. 



Genus 3. Lankesicrclla, Labbe, 1899. (Syn., Drepanidium Lank., 1882.) The 

 parasite is not more than three-quarters of the length of the blood cell of the 

 frog in which it lives. Many species in many different species of frogs and 

 toads. Life history not yet satisfactorily worked out; according to Hintze, 

 it is completed in the frog's blood and digestive tract; according to Billet, 

 it involves a trypanosome phase analogous to that of Halteridium, as described 

 by Schaudinn (Hemoproteus). Further observations are much needed. 



Genus 4. Hemogregarina, Danilewsky, 1885. The body of the parasite exceeds 

 the length of the blood cells of reptiles which it infests, and is bent in the form 

 of the letter V. Life history unknown, although varied observations have 

 been recorded in connection with the ten or more species that have been 

 described (see Liihe). 



Genus 5. Hepatazoon, Miller, 1908. A liver cell, and blood parasite of rats. 

 Schizogony in liver cells, engulfing and encapsulation in leukocytes, dissolu- 

 tion of capsule and copulation of gametes in the digestive tract of the inter- 

 mediate host (a gamasid mite, Lelaps echidninus); sporulation in the body 

 cavity of the mite, ingestion of the mite and its parasites by rat, penetration 

 of gut wall by sporozoites and new infection of liver cells. One species, H. 

 perniciosum, Miller, 1908 (Fig. 106, p. 271). 



Class II. NEOSPORIDIA, Schaudinn. Sporulation of the ameboid parasites takes 

 place during the activity of the parent cell and without interfering with the 

 vegetative processes. Celozoic, histozoic, or cytozoic parasites, mainly of 

 vertebrate hosts, and especially of fish. 



Order 1 . Myxosporidia, Biitschli. Relatively large neosporidia reproducing by 

 pansporoblast formation, the spores provided with polar capsules containing 

 more or less easily seen threads. 



Suborder 1. DISPOREA, Doflein, 1901. One pansporoblast containing two spores, 

 produced by each trophozoite. Spores wider than long. Trophozoites float- 

 ing freely in the fluids of various organs of fish hosts and frog hosts. 



Family 1. Ceratomyxidce, Doflein. With the characters of the suborder. 



Genus 1. Ccratomyxa, Thelohan, 1892. The two valves of the spore produced 

 into long attenuated processes. About nine species, mostly from the gall- 

 bladders of fishes (Fig. 20, G}. 



Genus 2. Leptotheca, Thelohan, 1895. Valves of the spore not drawn out into long 

 processes. The sporoplasm completely fills the spore membranes. About 

 six species from the gall-bladders of fishes and the kidneys of frogs (Fig. 20, 7). 



Suborder 2. POLYSPOREA, Doflein. More than two spores, usually a great num- 

 ber, produced in each pansporoblast. The spores are longer than wide. 



