The Nervous System and the Senses 169 
color. It is asserted that ants do not perceive red light 
and the same statement is made concerning bees, but 
this is incorrect for bees. It is also sometimes said that in¬ 
sects perceive some of the ultraviolet rays, beyond the range 
of human vision. The color preferences of bees have also 
been observed, it often being stated that they prefer blue. 
It seems certain that bees do not see objects distinctly 
and their vision is clearly far less acute than that of wasps 
and some other insects. Perhaps they do not perceive the 
form of objects at all. The relative intensity of light is 
probably an important part of their vision. When it is re¬ 
called that the hairs (p. 104) cover many facets of the com¬ 
pound eye, especially in younger bees, and that the structure 
of the eyes does not suggest a high degree of efficiency in 
vision, it becomes a matter of wonder that bees are helped 
by vision as much as appears to be the case. 
Smell. 
It is commonly believed that bees possess an acute sense 
of smell, and this belief is borne out by experiments on this 
subject. With the exception of qualifying statements by 
Lubbock 1 and Forel, this is usually conceded. The location 
of the olfactory organs is a matter of much less unanimity 
of opinion. Mclndoo 2 has recently performed a valuable 
service in gathering together the literature on the olfactory 
organs in insects and it is necessary only to give a list of the 
organs which are supposed to carry the olfactory organs to 
show the confusion which has existed. These sense organs 
have been located by various authors on the following struc¬ 
tures : (1) the spiracles, (2) organs close to the spiracles, 
(3) glands of head and thorax, (4) oesophagus, (5) “internal 
superior surface,” (6) folded skin beneath antennae, (7) 
rhinarium, (8) plate between eyes and beneath antennae, 
1 Lubbock, Sir John, 1899. The senses, instincts and intelligence of 
animals. Internat. Sc. Ser. London., vol. 65. 
2 Mclndoo, N. E., 1914. The olfactory sense of insects. Smithsonian 
misc. col. LXIII, no. 9, 63 pp. 
