62 



projecting chin (i), like a fleet of boats doubling a bold headland, and 

 lodge themselves one after another in the little cup-like receptacle 

 beneath. The action of the cilia which perform this transport is 

 clearly seen ; and I believe that they are continuous from the great 

 sinus to the cup. The contents of the cup are whirled round with 

 great rapidity, and it was while looking at this spectacle, that the 

 notion occurred to me, that the pellets of the case might be prepared 

 in this receptacle. Dr. Mantell, in his interesting ' Thoughts on 

 Animalcules ' (p. 60), had informed us that the pellets are coloured 

 with admixed pigment ; but he supposed with Dr. Ehrenberg, whose 

 observations I shall presently quote, that they were expelled from 

 the orifice of the rectum. 



I now watched the animal with eager expectation, and presently 

 had the satisfaction of seeing it bend forward its head as I had ex- 

 pected, and after a second or two raise it again, when I saw that the 

 little cup had lost its contents. It immediately began to fill again ; and 

 when it was full, and the contents were consolidated by rotation, aided 

 probably by the admixture of a salivary secretion, it was again bent 

 down to the margin of the case, and emptied of its pellet. This pro- 

 cess I saw repeated many times in succession, until a goodly array 

 of dark red pellets were laid upon the yellowish brown ones, but 

 very irregularly. After a certain number were deposited in one part, 

 the animal would suddenly turn itself round in its case, and deposit 

 some in another part. It took from two and a half to three and a 

 half minutes to make and deposit a pellet. Some atoms of the 

 floating carmine now and then passed down the oesophagus into the 

 gizzard, and thence into the stomach ; but these were quite inde- 

 pendent of, and unconnected with, the pellets, which were composed 

 exclusively out of the torrent that had passed off the disk. On one 

 occasion the cup was brought down to the margin, but, from some 

 cause or other, failed to deposit its pellet: it was raised for a 

 moment, and then a second attempt was made, which was successful. 



Professor Ehrenberg, however, thus speaks of the phenomenon in 

 question : — " According to my own observations, the tubes are com- 

 posed of little lenticular bodies, which the animal (as Leeuwenhoek 

 indistinctly saw, but I distinctly discovered) separates from the pos- 

 terior intestinal orifice (am der hintern Darmiindung) and glues fast 

 with the same. Therefore the tube is always of the same height as 

 this part of the animal. These granules are not extraneous bodies, 

 like those on the tube of Phryganea, nor are they excrement ; but a 



