ACTINOMYXIDIA 



I8 7 



Order. Actinomyxidia, Stole. 



A brief mention may be made of the Actinomyxidia (fig. 101), which were first 

 described by Stole in 1899 as parasites of Oligochsetes. They have also been 

 investigated by Mrazek, and a detailed study of certain species was made by 

 Caullery and Mesnil (1905). The tropho- 

 zoite is small and amoeboid.. The spores 

 are large, and exhibit tri-radiate symmetry. 

 Spore formation is complicated and sexual 

 processes occur therein. Many amcebulse 

 are set free from each spore. 



Order. Sarcosporidia, Balbiani. 



The first member of this group was 

 discovered by Miescher in 1843. This 

 author found white filaments running 

 parallel with the direction of the fibres 

 in the voluntary muscles of mice. They 

 were visible to the naked eye, and proved 

 to be cylindrical tubes tapering at each 

 end. They were as long as the muscular 

 fibres, were enveloped in a membrane, and 

 contained innumerable elongate or kid- 

 ney-shaped bodies and a smaller number 

 of little spherical forms. Th. v. Hessling 

 confirmed (1853) the occurrence of these 

 " Miescher's tubes " within the muscular 

 fibres, this author having discovered the 

 same structures in the heart muscles of 



deer, cattle, and sheep. Both investigators considered them to be pathological trans- 

 formations of the muscles, v. Siebold, from his own experiences, regarded them 

 as fungus-like entophytes. 



Rainey (1858) discovered similar structures in the muscular system of pigs, and 

 considered them to be early stages of Cysticercus cellulosce, which error Leuckart 

 rectified, simultaneously emphasizing their relationship with Myxosporidia. Both 

 these authors found them in the muscular fibres, and both observed that they 

 possessed a thick striated membrane. Manz (1867) published the results of more 

 minute investigations on the structure and contents of the cylinders. This observer 

 also recognized the disease in rabbits and attempted to cultivate the parasites. He 

 also tried to induce experimental infection in guinea-pigs, rats, and mice, but the 

 result was negative. 



However, domestic and wild mammals are not the only hosts of Sarcosporidia ; 

 these parasites are also harboured by birds. Thus, according to Kiihn, they are 

 found in the domestic fowl ; according to Rivolta in Turdus, Corvus, and other 

 birds ; according to Stiles in North American birds ; while Fantham found Sarco- 

 sporidia in the African mouse-bird, Coitus. Reptiles also are parasitized occasionally. 

 Bertram found them in the gecko, Liihe in the wall-lizard. It was found also that 

 the Sarcosporidia could develop not only in the muscles but also in the connective 

 tissue. This led to the foundation of a new, but provisional, classification by Blan- 

 chard, using the generic name Miescheria for the parasites in the muscles and 

 Balbiania for those in the connective tissue. Finally, Sarcosporidia have also been 

 observed in man. 



FIG. lor. Spore of Hexactinomyxon 

 psammoryctis. At top of .figure three polar 

 capsules, one with polar filament extended. 

 X 450. (Aftei Stole.) 



