Note 7 — Chapter XVI

The difficulty in conceiving this theory lies in the fact that the waves travel in straight lines. On the other hand, matter in a state of degradation may expel particles highly energised and of enormous velocity. Most antennæ are covered with hairs of inconceivable fineness; others may contain cavities of almost infinite minuteness. Is it not thinkable that they are able to detect, in the gaseous atmosphere, floating particles that are not gaseous? This would not prevent the specialisation of antennæ as mere feelers in some insects and crustaceans. The difficulty of such a supposition lies in the fact of discrimination; but if we did not possess a sense of taste or smell discrimination would seem inconceivable in their case also.—[Trans.]