130 PROCEEDINGS OF THE ACADEMY OF [PaRT I 



Burck (6: page 183) discusses in a few lines the evacuation of 

 foecal material: "As regards defecation, my opinion is the same as 

 that of Clark and Biitschli, who observed the elimination of digested 

 food to take place very near the base of the flagellum inside the 

 plasmatic collar." And further on he adds: "An evacuation of 

 ingesta at any point of the body surface, as Fisch supposes it to 

 occur, is certainly not correct." Though agreeing with these 

 statements in general, I should propose a slight restriction concern- 

 ing the last of these conclusions: if it must be considered certain 

 that the evacuation of foeces is not possible at all points of the 

 body indiscriminately, an exception ought to be made at least for 

 the plasmatic funnel; I have often seen captured granules (which 

 very likely were not to the taste of the animalcule) slowly glide 

 upwards, and when near the very border of the funnel, be suddenly 

 hurled away (as if by a sharp undulation of the border?), and curi- 

 ously enough, these very small granules or microbes, which were 

 probably provided with invisible fiagella, after having proved quite 

 inert and unmoved as long as they were included in the vacuole, 

 when cast out at once began to toss about in a rapid dance, soon 

 disappearing. 



On the 9th and 10th of February, I met with a considerable num- 

 ber of small naked Flagellates (Plate VII, fig. 34), which could be 

 referred without any hesitation to this same species; the size, the 

 two contractile vesicles, nucleus, flagellum, protoplasmic collar, 

 everything, in fact, indicated specimens which had left the shell 

 and had adopted a free life. They swam quickly about, in small 

 circles, without ever getting very far away; or they went straight 

 forwards, for a distance hardly more than five or six times their own 

 length, then stopped for a second or two, darted forwards again, 

 and so on for a long time, proceeding by sudden intermittent ad- 

 vances. Perhaps some correlation might be supposed to exist be- 

 tween this sort of progression and a very curious fact, other exam- 

 ples of which are hardly to be expected in the whole series of the 

 Flagellata, but which could easily be ascertained in each of the 

 specimens observed, namely, that the flagellum, instead of drawing 

 the body, was pushing it from behind; the flagellum, in fact, is pos- 

 terior. But the small animalcule has itself changed in shape, it 

 has shortened, and at the same time has taken the form of a top, 

 pointed in front (in front when swimming, in reality it is the hind 

 part of the body), and as for the plasmatic collar, it is seen reduced 

 to one-quarter of its former length, but is rather thick and very 



