ESTERLY: EUCALANUS. oe 
a body suspended in a vesicle, somewhat as an otolith rests in the 
ear-sac. ‘lhat this body is really composed of the two basal plates 
of the apposed cells, which have stained so deeply as to be indistin- 
guishable from each other, is shown when such a preparation is de- 
colorized. Figure 12 (Plate 2) gives, in a semi-diagrammatic way a 
rather typical condition that appears in sections of deeply colored 
vom Rath material; while Figure 11 (Plate 2) is drawn from the 
adjoining section of the same organ, after decolorization. Here 
the line of separation between the two cells and their basal plates is 
_ very plain, and from this figure may be learned the reason for the 
peculiar appearance shown in Plate 2, Figure 24, or Plate 3, Figure 36. 
The organs of Claus are provided with the interior bodies of Hesse 
(phaosomes), as are the retinal cells of the median eye. ‘The bodies 
are similar in all respects in the two structures, and it is therefore 
unnecessary to enter into a detailed description of their form in the 
organs of Claus except to state that the band-like appearance of the 
bodies is very rarely met with. ‘The arrangement of the bodies in the 
organs of Claus is rather uniformly around or near the periphery of 
the cell opposite the basal plate. ‘This is seen best in sections (Plate 
5, Fig. 55; Plate 3, Fig. 36), but also appears in whole preparations; 
it is difficult, however, to show the condition in proper perspective in a 
drawing. Figure 33 (Plate 3) will serve to give some idea of the 
conditions as seen in an entire preparation. But any description which 
deals with the arrangement of the interior bodies must be limited to 
the more general features. A comparison of Figures 33 and 34 (Plate 
3) is instructive as indicating something of the position of the interior 
bodies in the cells. Figure 33 is a drawing of the organ of Claus 
shown at the left in Figure 27 and viewed from the dorsal side, while 
Figure 34 is a drawing of the lateral face of a sagittal section of the 
same organ. In both, the interior bodies are farther from the basal 
plates than from the periphery of the cell opposite the plates, but many 
more are seen in the section (Fig. 34) than were apparent in the whole 
preparation (Fig. 33), if we limit our consideration to the cell (upper- 
most in the plate) farthest from the observer in each of the figures. 
There was really a long peripheral row of rod-like bodies ventral to 
those actually shown in the anterior cell of Figure 33, but it so hap- 
pened that in this particular case they were not visible at all. 
In general, then, it is a fair statement that the interior bodies of the 
organs of Claus are peripheral; that is, near that margin of the cell 
which is farthest from the basal plates. It can scarcely be said that 
the interior bodies have a definite arrangement or position in regard 
