210 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Parasites in Chiton and Patella. — Paul Debaisieux {C. R. Soc. 

 Biol, 1919, 82, 1400-2). In Chitons there are at least three distinct 

 parasitic Protozoa. In Acanthochites fascicularis the liver and the 

 epithelium of its ducts contain large numbers of FseudoJdossia chitonis 

 sp. n., while the salivary glands abound in stages of one of the Eimeridea. 

 In many organs of CraspidocMlus cinereus there is Haplospoiidium 

 chitonis (= Minchinia chitonis). In Patella vulgaris there is a new form, 

 FseudoJdossia patella sp. n. J. A. T. 



New Species of Haplosporidium. — Paul Debaisieux (C. R. Soc. 

 .Biol, 1919, 82, 1399-1400). In specimens of the long Nemertean 

 Lineus marimis there were very numerous spores of a new species of 

 Haplosporidium (H. nemertis). They occurred especially in the connec- 

 tive tissue between the gut and the longitudinal muscles, forming an 

 almost continuous layer. The youngest stages are subspherical and 

 binucleate masses — small plasmodia. These grow and show a multipli- 

 cation of nuclei, three to five divisions being observed. The nuclei 

 increase in size and undergo two more successive divisions ; the multi- 

 nucleate Plasmodium resolves itself into uninucleate sporoblasts, which 

 are transformed into spores. Some large plasmodia resolve themselves 

 into the binucleate forms mentioned above, which spread the infection in 

 the host. J. A. T. 



Nutrition of the Protozoa. The Growth of Paramoecia in Sterile 

 Culture Medium.— R. A. Peters {Proc. Phijs. Soc, 1920, 53, 108-9). 

 As a preliminary step to the study of the metabolism and reactions of 

 Paramoecia in solutions of known chemical composition, pure cultures 

 free from bacteria are needed. Cultures of a race of Paramoecia about 

 50 ft in length, isolated from a single individual, have been obtained in 

 the following medium : — 



Per cent. 



Sodium chloride . , . . . 0*06 



Potassium chloride ..... 0"0014 



Calcium chloride 0'0012 



Basic sodium phosphate (NaHPO) . . 0-0001 



Acid potassium phosphate (KHPO) . . O'OOOl 



Magnesium sulphate. .... 0*001 



Sodium bicarbonate 0-002 



Phenol red Trace 



Glucose . . . . . , .0*03 



Histidine O-Ql 



Arginine 0"01 



Leucine . . . . . . . 01 



Ammonium lactate ..... 0*003 



Ferric chloride ...... Trace 



Potassium iodide ..... Trace 



Manganous chloride ..... Trace 



The above substances are made up with glass-distilled water. The 

 constituents are autocluved separately. The final mixture is sterilized 

 by heating to 80°C. on three successive days. The reaction is adjusted 

 to PH = 7*4 with NaOH N/100. The organisms were cultivated in 

 sterile media in depression shdes, experiment showing the most suitable 

 concentration for division. After a number of individuals had been 



