324 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



club-shaped cells with a fine external membrane enclosing 

 a large number of granules of two kinds, some being much 

 larger than the others, and of a dark brownish hue. 

 Both kinds of granules are very inert, and stains and other 

 reagents have little or no effect upon them. 



If the body wall of the worm be ruptured, these cells, 

 which are very easily dislodged from the wall of the 

 intestine, can be liberated into the water. In the water 

 they swell considerably, and the two kinds of granules 

 which they contain can be clearly seen (PL III, fig. 14). 

 The larger ones tend to congregate near the centre of the 

 cell, the outline of which becomes rather indistinct and 

 shadowy when the cell is immersed in water. The smaller 

 granules can be more clearly seen near the periphery of 

 the cell where the larger granules are not so abundant. 

 All the granules of a cell which has been freshly liberated 

 from the body of a living worm exhibit active molecular 

 movements, and this movement is kept up for some time 

 if the wall of the cell is not broken. Gradually, 

 however, this molecular movement becomes slower and 

 slower until it finally ceases. The granules then appear 

 to congregate at one part of the cell, sometimes at the 

 side, sometimes nearer the middle, the rest of the cell 

 being quite clear and transparent. Probably this massing 

 together of the granules heralds the breaking down of 

 the cell. 



All these points in the structure of the chloragogen 

 cells can be made out in the fresh material. This amount 

 of investigation was carried out with considerable care 

 by Mcintosh, and his results were published in his paper 

 entitled "On some points in the structure of Tubifex " 

 (1871). In quoting Dr. Buchholz' paper " Beitrage zur 

 Anat: der Gattung Enchytrseus " (1862), Mcintosh 

 mentions that this author has put a distinct nucleus in 



