ttECENT MEMOIRS ON FRESHWATER RHIZOPODA. 339 



denced by the vigorously tremulous, or dancing movement 

 of these granules, that is to say, a distinctly expressed mole- 

 cular movement. In this Pelomyxa agrees with Actinosphse- 

 rium and other vacuole-bearing Sarcodina. The author 

 thinks this fluid must be simply water. 



Coming to the third question, the intervening substance 

 must be regarded as the real basic substance of the whole 

 inner space, and merely interrupted by the vacuoles. It is 

 hyaline, but filled with a great quantity of granules, some 

 dark-shining and large, others clearer and more minute, even 

 down to the finest puncta. This basic substance is further 

 the matrix for all the other structures to be mentioned, and 

 is the vehicle inclosing the food, &c. 



The body-mass thus is seen to consist of pure protoplasm 

 composed of two strata, an outer cortical one and an inner 

 parenchyme. The former is hyaline and homogeneous. It 

 is the chief seat of contractility, and hence in it the loco- 

 motive power resides . The whole inner parenchyme is of 

 thinner consistence, and is but passively moved; it is richly 

 granular and filled with watery vacuoles, often so crowded 

 that the substance appears reticulately interrupted. The 

 two strata are not sharply marked off", but pass off gradually 

 into one another. 



In the so composed body-mass there occur further three 

 structures — (1) the nuclei; (2) hyaline and homogeneous 

 bodies of roundish, ovoid, or irregular figure, of glassy appear- 

 ance (the " Glanzkorper" of the author) ; and (3) fine bacilli- 

 form bodies. 



The occurrence of the nuclei in considerable numbers 

 becomes in so far a principal character for Pelomyxa. They 

 lie in the inner space, irregularly distributed between the 

 vacuoles, more numerously in the middle of the body, more 

 sparingly outwardly (fig, 11). In examples, say one milli- 

 meter, in diameter, there may be some hundreds. They are 

 delicately-walled bodies of globular, more rarely oval, figure, 

 as a mean about 0*012 millimetres in diameter, with hyaline 

 contents, pervaded more or less by dark granules. Their 

 position, form, and appearance, give in all respects the indu- 

 bitable impression Of cell-nuclei. Acetic acid and alkalies 

 do not cause any coagulation, but a solution of the contents. 

 Alcohol causes a coagulation of the contents, which be- 

 come darker. Tincture of iodine produces the same effect, 

 at the same time the contents becoming dark brown. The 

 author sometimes thought he recognised a second inner 

 contour — a nucleolus — but only rarely, and at best but 

 indistinctly. 



VOL. XVII.TBsNEW SEB, Z 



