166 SUMMARY OF CURRENT RESEARCHES RELATING TO 



ing glands. The macrogametes probably also copulate with the micro- 

 gametes, and the thick-shelled cysts no doubt arise from their union. 

 These cysts produce resting-spores by exogenous sporulation, the rest- 

 ing-spores being the agents by means of which the infection of new 

 animals, or autoinfection of distant parts of the body, occurs. The 

 parts affected are usually those parts of the body which the animals 

 are in the habit of rubbing, and the disease probably results from the 

 animals rubbing themselves against infected pens. 



Psorospermic Tumours of Xiphias.* — Dr. L. Facciola describes the 

 so-called psorospermic tumours in the muscles of Xiphias gladius, 

 which, he thinks, are due to a stage in the development of Gregarina 

 mulleriana. 



New Myxosporidian in Fishes. f — E. E. Tyzzer gives a short 

 account of tumours and Sporozoa in fishes, and describes a new form, 

 which occurs in minute cysts in the muscles of herring, alewife, scup, 

 menhaden, hickory shad, and cunner, especially in the younger speci- 

 mens. The spores are quadrilateral when seen face on, and oval in 

 profile ; they show a tendency to occur fitted together in clumps of 

 four or eight. Each spore contains four capsules, very delicate pale 

 green in colour, radiating from the anterior extremity toward the four 

 corners, and extruding vibrating filaments which cause movement. 

 After a time the filaments shorten and return into the capsules. 



* Neptunia, xv. (1900) pp. 197-202. 



t Journ. Boston Soc. Med. 8ci., v. (1900) pp. G3-8 (1 pi.). 



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