448 PROTOZOOLOGY 



larynx (Baraban and St. Remy), in muscles of biceps and tongue 

 (Darling), in cardiac muscles (Manifold), etc.; parasites in mus- 

 cles. 1.6 mm. by 170^i, elongate spindle, wall thin, contents di- 

 vided into numerous chambers, spores banana-form, 8-9^t long 

 (Baraban and St. Remy); parasites 84ju by 27m, spores 4.25/x by 

 1.75m (Darling); parasites spherical, 500m in diameter (Mani- 

 fold). 



S. tenella Railliet (Figs. 204, a; 205). In muscles of tongue, 

 pharynx, oesophagus, larynx, neck, heart, etc., of sheep; large 

 parasites 40m-2 cm. long with a thin membrane; spores sickle- 

 form. 



S. miescheriana (Kiihn) (Fig. 204, h). In muscles of pig; para- 

 sitic mass up to 3-4 mm. by 3 mm; envelope striated; spores reni- 

 form, capable of division when young (Manz). 



*S. bertrami Doflein. In muscles of horses; similar to *S. miescher- 

 iana; parasitic mass up to 9-10 mm; envelope striated. 



S. muris Blanchard. In body muscles of rats and mice; para- 

 sitic masses up to 3 cm; spores 13-15m by 2.5-3m; transmissible 

 to guinea pig (Negri) which shows infection in muscles in 50-100 

 days after feeding on infected muscles. 



Order 2 Haplosporidia Caullery et Mesnil 



This order includes those sporozoans which produce simple 

 spores. In some species the spores may resemble superficially 

 those of Microsporidia, but do not possess the polar filament. The 

 exact boundaries and affinities of this order to other groups are to 

 be determined by future investigators. 



The Haplosporidia are cytozoic, histozoic, or coelozoic para- 

 sites of invertebrates and lower vertebrates. The spore is spherical 

 or ellipsoidal in form and covered by a resistant membrane which 

 may possess ridges or may be prolonged into a more or less long 

 tail-like projection. In a few species the spore membrane possesses 

 a Hd which, when opened, will enable the sporoplasm to emerge as 

 an amoebula. The sporoplasm is uninucleate and fills the intra- 

 sporal cavity. 



The development of a haplosporidian, Ichthyosporidium gigan- 

 teum, as worked out by Swarczewsky, is as follows (Fig. 206) : The 

 spores germinate in the alimentary canal of the host fish and the 

 sporoplasms make their way to the connective tissue of various 

 organs (a). These amoebulae grow and their nuclei multiply in 



