306 SUMMARY OF CURRENT RESEARCHES RELATING TO 



about with great rapidity, endeavouring to conceal themselves beneath 

 any vegetable matter on the slip, their motions gradually growing 

 slower ; then they revolved slowly two or three times. A sudden 

 contraction of the body followed, and in a few seconds the appearance 

 shown in Mr. Waddington's illustrations. 



The regularity of the fine transparent acicular fringe that now 

 surrounded the animalcule, or whether it was completely thrown oflf, 

 appeared to depend, as described by Mr. Waddington, on the strength 

 of the solution. In those cases where the appendages were separated 

 from the body, it was not unusual to find a few spiral shaped, although 

 after careful comparison the majority were rod-like. 



After examination of numerous specimens treated with the acid, 

 it seemed difficult to reconcile cilia of such length — in some cases 

 exceeding the width of the body — with the action apparent in the 

 ciliary movements of the living animalcule. But while observing an 

 example under oblique illumination, Mr. Gilliatt was struck with the 

 appearance of fine lines across it, and was thus reminded of the rod- 

 like bodies or trichocysts so fully developed beneath the cuticle of 

 P. aurelia ; and after referring to the views of W. S. Kent, Stein, 

 AUman, and Ellis, on the efiects produced "on the trichocysts by 

 the use of acetic acid, or a small stalk of Geranium zonale (Horseshoe 

 Geranium), he considers that it may be " fairly concluded that the 

 effects observed by Mr. Waddington in his experiments must be 

 attributed to the action of tannic acid on the trichocysts of Parame- 

 cium aurelia, and not, as he considers, to its action on the cilia." 



Professor D. S. Kellicott * has also satisfied himself that the bodies 

 are trichocysts. Glycerole of tannin acts even more energetically 

 than acetic acid, and is, he considers, sure to become a valuable 

 reagent in the study of infusoria. By applying in proper dilution, 

 the infusorian is not at once killed, and the cilia may be seen yet in 

 motion, with the trichocysts extending far beyond them. 



Another writer | refers to " the hirsute covering of Paramecium 

 and other infusoria shown when a solution of quinine is added to 

 the water in which they live, although the cilia are quite invisible 

 when the animals are swimming about. Quinine may prove to be a 

 valuable reagent for killing the infusoria and rendering their cilia 

 visible." 



Preparing Fresh-water Rhizopoda.J — In fixing the living animal, 

 K. J. Taranek uses small (8-10 cm. long) pieces of soft red blotting- 

 paper of triangular shape, and, in order to draw off the water under 

 the cover-glass, lays a piece of this paper upon the slide in such wise 

 that the point of it reaches the edge of the cover-glass, and comes in 

 contact with the water beneath. The blotting-paper immediately 

 causes a current, which, how^ever, is very weak, as only the corner 

 of the paper is active. If the current is strong, so that the animal 

 begins to move with the water, the paper must be removed ; but if 



* Bull. Buflfalo Nat. Field Club, i. (1883) p. 110. 

 t Engl. Mech., xxxviii. (1883). 



X Abh. math.-naturwiss. CI. K. Bohtn. Gesell. Wiss., xi. (1882) Art. No. 8, 

 iv. and 56 pp. (5 pis.). See also supra, p. 247. 



