ANOTHER WORLD DOWN HERE. 47 



organs that are highly suggestive of the movements of the 

 old semaphore telegraph arms. 



The most generally received opinion is that these an- 

 tennas are very delicate organs of touch, but some recent 

 experiments made by Gustav Hansen indicate that they are 

 organs of smelling or of some similar power of distinguish- 

 ing objects at a distance. Flies deprived of their antenna 

 ceased to display any interest in tainted meat that had pre- 

 viously proved very attractive. Other insects similarly 

 treated appear to become indifferent to odors generally. 

 He shows that the development of the antennae in different 

 species corresponds to the power of smelling which they 

 seem to possess. 



I am sorely tempted to add another argument to those 

 brought forward by Hansen, viz. : that our own olfactory 

 nerves, and those of all our near mammalian relations, are 

 curiously like a pair of antennas. 



There are two elements in a nervous structure the gray 

 and the white; the gray, or ganglionic portion, is supposed 

 to be the centre or seat of nervous power, and the white 

 medullary or fibrous portion merely the conductor of nerv- 

 ous energy. 



The nerves of the other senses have their ganglia seated 

 internally, and bundles of tubular white threads spread 

 outwards therefrom; but not so with the olfactory nervous 

 apparatus. These present two horn-like projections that 

 are thrust forward from the base of the brain, and have 

 white or medullary stems that terminate outwardly or an- 

 teriorly in ganglionic bulbs resting upon what I may call the 

 roof of the nose; these bulbs throw out fibres that are com- 

 posed, rather paradoxically, of more gray matter than white. 

 In some quadrupeds with great power of smell, the olfactory 

 nerves extend so far forward as to protrude beyond the front 

 of the hemispheres of the brain, with bulbous terminations 

 relatively very much larger than those of man. 



They thus appear like veritable antennae. In some of 

 our best works on anatomy of the brain (Solly, for example) 

 a series of comparative pictures of the brains Of different 

 animals is shown, extending from man to the cod-fish. As 

 we proceed downwards, the horn-like projection of the ol- 



