ii GUSTAV EISEN: PONTOSCOI 



11 



plasm. The appearance under a low power is exactly that given in Dr. Hoi 



figure; but below the central cap we find also a floor, which in 



like a bar or shuttle, thicker in the middle, and evidently com] 



quality of cytoplasm as the central cap. This cap and the floor a with 



each other by means of a hollow cylinder of cytoplasm, staining 



io, etc., c. cy.). This cylinder is, as far as 1 



very thin, generally smooth and even, but varying greatly m 



the cylinder is as high as the central cap (fig. io), in others much sh< 



15), while now and then we find a cell in which the cap and the fli 



diately as in figure 12. Sometimes again there is (in 1 m) a slij 



ekvation of cytoplasm from the floor to the cylinder, as in figures 11 an r it 



may exist only on one side as in fig. 7. The form of the central cap varies lc.it 



little. It is somewhat lunate, with the concave side shallow and with tin hon 



but sharply pointed. The crescent is thus always pointing downward- , cap 



covers the nucleus more or less closely, sometin 



between the nucleus and itself, as seen in fig. 11. 



The floor, which consists of the same kind of cytoplasm as that which com- 

 poses the cap, stretches across the lower part of the cell in al! di aving a 

 space between its under surface and the lower part ol the cytotheca. It is alw 

 thicker in the center, where it stands in connection with the cylinder, and through it 

 with the cap. It thins out towards the cell wall and becomes lure vacuoled. Tl 

 readily seen in oblique sections, where a surface view ol the floor i- had. 

 The floor is generally elevated, upward convex, rarely the contrary. 



In the meshes of this reticulation, especially of the cap, is seen a very highly 

 refractive substance, which I consider to be the one which gives the whole cell the 

 certain brilliancy, mentioned by all observers; but this refractive substance is not 

 present in the spaces outside of the cap and the floor. 



Below this more central floor is found a lowest floor of cytoplasm, attached 

 to the bottom wall of the cell, and situated entirely below the main floor. This low- 

 est cytoplasmic layer is laminated, and presents the appearam given in fig 

 14 and 15. It stains but faintly with cosin or orange G., but mon jly with 

 Congo-red. Between this layer and the floor are seen numerous cytoplasmic thri 

 a mass of spongy cytoplasm, staining wry faintly. 



The central cap and the floor both consist of similarly reticulated cytoplasm, 

 which stains most intensely, and almost to the same di rywhere. It 1- 



strongly and beautifully reticulated. When the focus is on the surface of the 

 it is seen that the reticulation consists of even meshes, but when the fo< 



