PEROPHORA ANNECTENS. 47 



never show as anything else than granules. They are so 

 excessively small that I have not, even w^ith a yV oil 

 immersion objective, been able to determine much of their 

 nature. From what I have seen in a single specimen 

 stained in borax carmine, I have thought it possible that 

 they may be bacteria. My grounds for this conjecture 

 are not, however, very good. 



It is a fact worth mentioning, perhaps, that in many 

 cases there is a layer on the external surface of the test 

 that takes the stain considerably more readily than do its 

 remaining portions. This I have observed in sections 

 stained in various ways. The layer is not, however, an 

 external epithelium, such as is described by Maurice 

 ('88, p. 58), in the larva of Fragroides. There is, I be- 

 lieve, but one kind of cells in the test, and this is an im- 

 portant fact in connection with what I shall maintain to 

 be their origin. Figs. 29 and 30, pi. iii, represent portions 

 of test containing several of these cells. The tigure was 

 drawn with great care, with the aid of a Powell and Le- 

 land y'j oil immersion objective. The more usual condi- 

 tion is that shown in fig. 29. Here the cells are seen to 

 be situated in cavities which they do not fill. The nuclei 

 are by far the most distinct parts of the cells. Indeed, it 

 is not until one examines them very carefully with high 

 magnification and with the most favorable light, that he 

 is able to convince himself that a cell-body can be seen 

 at all. 



I have not attempted to represent the spaces in which 

 the cells are situated in any of the other figures, and in 

 many cases they cannot be seen. Occasionalh' one finds 

 cells in which the protoplasm is stained somewhat, though 

 never so deeply as the nucleus. Instances of this kind 

 are seen at m. c." , figs. 29 and 30. It happens not in- 

 frequently that two cells are found in one capsule (fig. 



