EsTERLY. — Eucalauus. 



PLATE 3. 



Fig. 25. Dorsal aspect of part of a frontal section of the brain. Vom Rath's 

 fluid IS hours, decolorized in hydrogen peroxide. It shows one 

 cell of the right organ of Glaus and its nerve in relation to the 

 neuropil mass of the brain. The section is the most ventral of 

 three which show the organ of Glaus. The basal plate was re- 

 moved with the two more dorsal sections, so it is evident that 

 the nerve leaves the cell on the side opposite to that of the basal 

 plate. X 405. 



Fig. 26. The cell of the organ of Glaus shown in Figure 25, enlarged to 665 

 diameters, showing the course of the fibrillae and the arrangeinent 

 of phaosomes. 



Fig. 27. Anterior part of brain, organs of Glaus and parts of optic nerve, 

 frontal nerves, and antennal nerves. Entire preparation seen 

 from dorsal side. Vom Rath's fluid 18 hours, pyroligneous acid 

 4§ hours; decolorized. X 305. 



Fig. 28. Right face of a sagittal section of an organ of Glaus. Vom Rath's- 

 fluid 18 hours; decolorized. The general form of the two basal 

 plates as seen in this section is the same as in cross sections 

 (Plate 2, Fig. IS) or in frontal sections (Plate 2, Fig. 11). The 

 interior bodies are rod-like and lie around the periphery of the 

 cell. X 665. 



Fig. 29. The most dorsal of the frontal sections of the organ of Glaus in the 

 series of which Figure 26 is the most ventral. The intermediate 

 bodies, part of the basal plate, and nerve are shown. The nerve 

 leaves the cell at a point opposite the basal plate. X 665. 



Fig. 30. The middle section in the series shown in Figures 29, 30 and 26. 

 The interior bodies are few compared with those found in the other 

 two sections, and the extent of the basal plates is greater. X 665. 



Fig. 31. Ventral view of entire organ of Glaus. Vom Rath's fluid 18 hours, 

 pyroligneous acid 4i hours, decolorized. The deep (dorsal) 

 cell has been drawn in detail (outline pale); the ventral cell is 

 drawn with a sharp outline, but besides the outline only the nu- 

 cleus and some phaosomes are reproduced. The basal plates 

 are not shown in either cell. X 665. 



Fig. 32. Anterior face of a cross-section of a part of the brain, the right organ 

 of Glaus and right antennal nerve. The organ of Glaus, it will be 

 observed, is on the opposite side of the brain from that shown in 

 Plate 2, Figure IS. The difference between the two cases in the 

 position of the line of contact of the two cells should be noted. 

 X 665. 



