ESTERLY: EUCALANUS. 19 
coincides with the chief axis of the eye. ‘The cells which adjoin the 
central one, above and below, are, respectively the central cell of the 
upper and lower groups; the long axes of these cells are nearly at right 
angles to each other. ‘The long axis of the dorsal cell is parallel to 
the dorso-ventral axis of the median eye, while the axis of the ventral 
cell is perpendicular to the median plane of the body. Similar rela- 
tions are shown in the cross sections of the eye represented in Figure 9 
(Plate 1) and Figure 23 (Plate 2). 
An examination of frontal sections (Plate 1, Figs. 2, 5) through the 
lateral eyes, or of entire preparations (Plate 1, Fig. 10, Plate 2, Fig. 22) 
gives an idea of the position of the axes of some of the other cells of 
the lateral eyes. It will be seen in Figures 2 and 5 (Plate 1) that the 
axes of the peripheral cells of a group if prolonged would meet at an 
angle of about 90° at their outer ends. In Figure 2 the three nuclei 
shown in each of the lateral eyes belong to the cells of the median group 
of three. ‘The central cell is seen to be triangular in outline, and the 
anterior and posterior cells are elongated. In Figure 22 (Plate 2) the 
outlines of the cells in the right lateral eye are shown, but merely in 
the most general way, for it is impossible to indicate the cell walls in 
perspective, and even if it were attempted, the result would be con- 
fusing. But the figure shows well enough the relations that the axes 
of the anterior and posterior cells of the groups bear to each other, 
and it also indicates the general shape of the various.cells, the cen- 
tral ones of each group being triangular, the others more elongated 
and extending from the base of the cup to its outer margin. 
With the relations of the axes of the cells of the lateral eyes in mind, 
inspection of such a cross section as is shown in Figure 7 (Plate 1) 
will convince one that the interior bodies have an arrangement that 
corresponds, at least in a general way, with the long axis of the cell. 
It will be seen that in the three cells forming in this section the median 
border of the lateral eyes these bodies are so arranged that they lie 
lengthwise of the cells. Not all the interior bodies have been repre- 
sented in this drawing, but special care has been taken not to select 
those only which would prove the point here contended for. ‘The 
illustration gives an accurate general idea of the arrangement of the 
rod-like or spindle-like bodies in the central cells. Even in such a 
seemingly heterogeneous assemblage of interior bodies as is shown in 
the lateral eyes in Figure 9 (Plate 1), a definite arrangement with 
reference to the cells is apparent; and the same may be said of Figure 
23 (Plate 2). 
In frontal sections a similar arrangement of the interior bodies with 
