614 THE SENSES AND SENSORY ORGANS. 
thick-set stylets which are found in another part of the 
ganglion.’ 
Lee’s description of this organ, so far as my observations go, 
is correct; but he was quite wrong when he denied the chordo- 
tonal character of the end organs in the scale and cupola. I 
can only explain this on the supposition that he worked with 
imperfectly fixed specimens, as it is only occasionally that 
sections exhibit the chordotonal organs of the cupola and 
scale, and it is probable that the chordotonal threads are 
easily torn away by the razor in cutting the sections. 
The various appearances presented by the chordotonal 
organs of the halteres are very difficult to understand. That 
Fic. 80.—Three groups of chordotonal organs from the halter of a Blow-fly, seen 
with a 4 inch objective. 4, from the cupola; 4, from Lees organ; and C, 
from the scala inferior and adjacent integument. 
there are two kinds is indubitable, and in general the slender 
rods are found in the smaller groups, whilst those of the 
cupola and scape are the larger form. In some sections, 
evidently through the scala inferior, I have observed small 
chordotonal organs in groups (Fig. 80). These are, I be- 
lieve, only found close to Lee’s organ. 
c. On the Functions of the Halteres. 
The halteres have been regarded by various authors as— 
(1) sound-producing organs; (2) olfactory organs; (3) organs 
