16 bulletin: museum of comparative zoology. 



I can confirm his statements as to their position in general; hut the 

 bodies also occur almost at random in the cell, for in anv series of 

 sections it may be seen that they may lie between the nucleus and 

 basal plates, or peripheral to the nucleus, as well as around it. It 

 is true that they are found most numerously between the basal ])late 

 (probably the region of Hesse's "Stiftchensaum") and the nucleus. 

 That this statement is correct for the lateral eyes, will be readily seen 

 whatever the plane of section, and for the ventral eye in both sagittal 

 (Plate 5, Fig. 46; Plate 1, Figs. 2, 3, pha'so.) and transverse (Plate 5, 

 Fig. 50) sections. Frontal sections of the ventral eye (Plate 1, Fig. 8) 

 show that the interior bodies are more numerous in the region between 

 the nucleus and the median plane of the eye, than in the outer por- 

 tions. But in any case the interior bodies are found less frequently 

 lateral to the nucleus of a cell. This is shown in Figure 8 and ap- 

 pears also in all other regions of the eye. 



I have been unable to confirm Hesse's statement that the rod-like 

 bodies which appear to be isolated are sections of a ribbon-like or 

 band-like, structure. My belief is that the interior bodies are really 

 and only rod-like, or spicule-like, though ribbon-like bands are seen 

 occasionally. One of these is shown in the right cell of the uppermost 

 pair of Figure 8; but they are so infrequent and the appearance is so 

 confused that the conclusion is almost forced upon one that in such 

 cases they are so crowded together that their actual structure is not 

 seen. It is easy to recognize the interior bodies in entire preparations 

 of the eye, and I have never seen a band-like body in any preparations 

 of that kind. 



On the other hand, it is possible, if one foUoAvs many series, to find 

 transitional forms between such closely aggregated groups of sjiicules 

 as appear in Figure 8, and the ribbon-like forms. In Figure 2 (pha'so.) 

 are shown several cases where it is plain that the structures which 

 appear to be bands are in reality made up of numbers of single rods 

 closely gathered together. The bands appear most frequently in 

 material either stained deeply in vom Rath's fluid or very lightly 

 in haematoxylin ; in the one case the real structure is hidden by excess: 

 of stain, and in the other it is not brought out. I think that the non- 

 ap])earance of bands in whole preparations almost precludes the 

 possibility that these bodies are bands, and there can be no doubt at 

 all that interior bodies occur as rods or spicules completely isolated 

 from all other structures of the same sort. It must be admitted, 

 however, that what seem to be band-like structures really appear in 

 the retinal cells, as Hesse (:01) has stated and shown in his figure 



