STUDY or PELOMTSA PALUSTBIS. 387 



"With a view to ascertaining whether the bodies were albuminous, 

 or albuminoid, almost every known micro-chemical test for 

 albumins was applied ; these tests are not numerous, and most 

 are not decisive, but were found to give the reaction, said to be 

 characteristic, equally well with the refringent bodies and with 

 almost anything else, e.g. the fingers of the operator, and even 

 with blotting-paper. The most reliable, however, appeared to be 

 (1) that with Millon's Eeagent, (2) the violet reaction with sugar 

 and sulphuric acid, (3) the xantlioproteic test, and (4) that with 

 caustic soda and copper sulphate. As far as my control 

 experiments went, none of these gave the reaction with wrono- 

 substances. 



Tlie Nature of the 'Refringent Bodies. 



The effect of these reagents as applied to the refringent bodies 

 was as follows, used on freshly-teased up Pelomyxcs taken from 

 water. On application of Millon's reagent there was no stainiuo- 

 at first, either of the protoplasm or of the refringent bodies. 

 Then a milky precipitate occurred, with coagulation of the 

 protoplasm, followed by the appearance of a yellowish tinge, and 

 the gradual disintegration both of the protoplasm and the 

 refringent bodies ; the latter collapsed, became nodular (PI. 37. 

 fig. 17), and ultimately dissolved. On warming, an hour after the 

 addition of the reagent, a delicate pink colour was observed in the 

 refringent bodies, and also in the protoplasm, vanishing on coolinw. 

 If heat was applied immediately, a deep pink colour was obtained, 

 but the bodies dissolved almost at once. Heating immediately, 

 but less strongly, gave a good pink colour, and the refringent 

 bodies only gradually disintegrated into nodules and disappeared. 

 The depth of colour evidently depended upon the degree of heat 

 applied immediately, but, if heated over a certain point, the 

 destruction of the bodies was too rapid to allow of the reaction 

 being observed. 



With strong sulphuric acid the refringent bodies were dis- 

 solved; sugar solution, run in afterwards, gave a very distinct, 

 but pale, violet coloration of the liquid. 



Strong nitric acid coagulated the protoplasm and shrivelled 

 everything up, but gave a pale yellow colour on heating, 

 deepening slightly on addition of ammonia. A17o solution of 

 caustic soda, followed by a very dilute solution of copper sulphate, 

 gave no violet coloration even on heating. 



