-19- 



of sections had to be studied before any conclusion could be 

 reached as to the minute structure of the cell g rou ps. The point- 

 ed ends of the cells are directed towards the opening (o.) of 

 the cell group, and, in the later stages at least, are usually 

 obscured by the mass of secretion which fills any space there 

 may be in the centre of the cell gro\ap. In practically every in- 

 stance there was a small protuberance at the opening of the cell 

 group (Fig. 5 g and Fig, 6 1, p.s.) which appeared to be a small 

 mass of secretion which had been forced out of the cell ^roup 

 by the contraction of the gland at fixation. There was no se- 

 cretion found in any other pert of the gland, which fact could 

 be explained only by supposing that the secretion was carried 

 away, as fast as it was formed, by the cilia. As seen in Fig. 6 1 

 (a camera drawing of a section of the next stage, magnified 

 925 diameters), the opening of the cell group is covered over 

 by a membrane which is continuous with the membrane from which ' 

 the cilia arise. As this membrane, in any given group, may be 

 followed without a break through a long series of sections, 

 p.nd the protuberance of secreted matter seen in each section, 

 it is difficult to see how the secretion gets on the outer side 

 of the membrane, unless It passes through a series of holes 

 in the membrane that, when filled as they are with secretion, 

 are too minute to be seen, even voider a magnification of 1200 

 diameters. 



In "Ig. 6 1 may be seen, just under the basement mem- 



