474 J. DUESBERG 



bedded in them. Each cell contains, in addition to these, a 

 few long chondriconts which could actually in some cases be fol- 

 lowed from the basal accumulation to the top of the cell, and 

 from there back to the basis. In the anterior part (fig. 6b), the 

 cells are crowded with long, sinuous and rather thin threads, 

 which, followed from the inner pole, are seen to circumscribe the 

 nucleus and intertwine with each other in the basis of the cell. 



Later, the cells of the branchial region of the digestive tract 

 become flattened, covering with a thin sheet the dense layer of 

 peculiar mesenchyme-cells described above, and the chondrio- 

 conts of these flattened cells run parallel to the surface (fig. 3). 

 Further posteriorly (fig. 6c), the disposition of the chondrio- 

 somes is very similar to the arrangement in the cells of the ante- 

 rior part in the preceding stage, but the cells themselves have 

 grown and differentiated a border. There is an accumulation of 

 chondriosomes below the nucleus and long chondrioconts are 

 found running through the whole cell-body; some of these can, 

 by careful focussing, be followed from one end to the other of 

 the cell. Whilst a number of these chondrioconts are perfectly 

 smooth, others bear swellings, sometimes a regular row of them. 

 Besides, the cells contain vacuoles, the content of which could 

 not be stained by the methods used, and granules of various 

 sizes, stained red in acid fuchsin preparations. Such an intes- 

 tine is obviously engaged in an active process of absorption. 



Figure 6d represents part of thev intestinal wall of an embryo- 

 trout, twenty-four days old. In each intestinal cell, one finds 

 two accumulations of chondriosomes, one above, the other below 

 the nucleus. Between these masses one may make out long 

 chondrioconts which, in some of the cells, bear swellings. Such a 

 disposition recalls exactly Champy's description ('11) of the 

 chondriosomes in the intestinal cell of higher vertebrates. In 

 the adult fish, they have been described by Corti ('13) who, in 

 Box salpa and in Trinca vulgaris, found a few short chondrio- 

 conts and an accumulation of chondriosomes in the distal part 

 of the cell of the fasting animal, whilst, during absorption, 

 vacuoles appear in the cytoplasm and the chondrioconts seem 

 to fall to pieces. I cannot help saying that the scarcity of chon- 



