C. Hay Murray 
311 
this organ in its general structure with the olfactory organs of the 
May Beetle, the Wasp, and Caloptenus, sketches of which (illustrating 
an article in Insect Life on The Senses of Insects, by the late Prof. 
C. V. Riley of America) are given (Fig. 34), it seems probable that it 
is this which gives the bed bug its power of distinguishing smells. The 
consensus of entomological opinion associates with the olfactory sense 
an organ of the above type of structure, viz. ampullae supplied with 
nerves. 
As already said, the cavity in which the olfactory organ lies, com¬ 
municates with the scent glands on either side (Figs. 13, 31). Moreover it 
OlfacloTL/ or^i 
in 
/Hay 3eeUe 
(Haiuer) 
Olfactory Oryan 
in 
Vespa. 
(/fauser) 
2)1 
Olfactory oryan 
in 
Caloptenus 
Olauser) 
The o-boi'e f/yures tvere traced from the ti/itstrations 
cf Prof. C. V ffI ley's arttc/e on "The Senses f JnsecC 
(Jnsecb /.ife Vol. 7, p. S') 
C. h'. M. 
Fig. 34. Sense organs of other insects. 
communicates with the exterior by an extremely small pore which lies in 
the middle line under the overhanging portion of the meta-thorax, and 
thus invisible from the ventral surface. How the sense of smell can be 
exercised by the bug is somewhat of a mystery, as the olfactory cavity 
not only communicates with the exterior but also with the glands, which 
secrete the same type of odour as the organ is evidently adapted to 
recognise. Possibly there may be a type of olfactory “ tuning,” to 
use a “ wireless'” term, which enables it to recognise outside odours. 
In no microtomed section made by the writer has he ever got any 
