CHAPTER XVII 

 THE SARCOSPORIDIA 



TECHNICAL SUGGESTIONS 



For the study of Sarcosporidia, small fragments of the muscle of 

 pigs should be examined under pressure as in the search for trichina>. 

 The small cysts of Sarcocystis miescheriana are not infrequently 

 mistaken by beginners for those of the worm. They may be crushed 

 and examined in the fresh condition for study of the spores. For 

 sections, heavily infected muscle is pinned out in an extended con- 

 dition and fixed for a half hour or more in picro-formol solution or in 

 Schaudinn's sublimate alcohol. If the latter is selected metal pins 

 must, of course, be avoided. Sections should be cut at 5/j. and at 10ju 

 and stained in hematoxylin and eosin, or, for details, in iron 

 hematoxylin. 



In many localities Sarcocystis tenella is readily obtained from the 

 oesophagus of sheep. Hartmann recommends feeding the finely cut 

 cysts in as fresh condition as possible to laboratory mice some two or 

 three months before needed. The cysts will be particularly numerous 

 in the muscles of the abdomen and of the legs of the infected mice. 



In connection with this practicum there may be demonstrated spores 

 of the Myxosporidia and Micros poridia, forms which can hardly be 

 studied in detail but which the student should be able to recognize. 

 We have found a Leptotheca from the kidneys of Rana pipicns a con- 

 venient and readily available illustration of the Myxosporidia, while 

 Nosema apis in the ventriculus of the honey bee is probably the most 

 widely distributed of the Microsporidia in this country. The more 

 famous Nosema bombycis can be obtained by purchase, if not other- 

 wise available. Abundant material from other sources is available in 

 every locality, and the important monographs of Kudo, 1919 and 

 1924, should be available in every laboratory. 



CHARACTERISTICS OF THE SARCOSPORIDIA 



The Sarcosporidia are parasitic in the muscles of vertebrates, 

 particularly mammals, and in a few cases have been reported for 

 man. They are also recorded for birds and reptiles. Many of 

 them are visible to the naked eye as whitish streaks or granules, 

 often called Miescher's tubes, in the muscle fibers. Within these 

 cysts are great numbers of thin-walled, sickle-shaped bodies called 

 spores, although they are not homologous with the spores of other 

 Sporozoa. Indeed the group is an aberrent one which, for reasons 



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