Ax§ 
oO) 
oY 
25 
i 
ri 
ET Pa BET SaE rea “I 5 = 
“ TSS OPN EAS fo 
— Kee ERED 
Figs. 19 to 26 Sections, showing detailed structure of chordotonal organ and 
ganglion cells. Fig. 19, semidiagrammatic drawing from several longitudinal 
sections through anterior portion at proximal end of hind tibia of a drone, twenty- 
one days old, showing chordotonal organ suspended in blood chamber, but at- 
tached at both ends to hypodermis (Hyp); X 320. Fig. 20, longitudinal view of 
one of the sensory elements from fig. 19, showing following parts in detail; sense 
cell (SC), axial tube (Ax), enveloping cell (EC), axial fiber (AF), cone (Con), 
cap cell (CC), and nuclei (Nuci, Nuce and Nuc3) of sense cell, enveloping cell 
‘and cap cell, respectively. Fig. 21, cross-section of sense cell (SC) through 
nucleus, showing tail end (large dot) of axial tube; figs. 22, 23, and 24, cross- 
sections of proximal end, of middle portion through nucleus, and of distal end, 
respectively, of enveloping cell, showing appearance of axial tube (Az) and its 
fiber (AF). Fig. 25, longitudinal section, and fig. 26, cross-section of ganglion 
cellsfrom tibia ofadrone. Figs. 20 to 26, X 1000. 
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