In justice to other observers I must say, however, that I am inclined to believe that in all beetles the antennæ in some way aid or assist audition, but they are adjuncts, as it were, and not absolutely necessary. It is a matter of easy demonstration to show that some of these insects hear less acutely where they are deprived of their antennæ. I presume they are about as necessary in audition as are the external appendages of the human ear; this, however, is mere supposition, and has no scientific warrant for its verity.
I have purposely said but very little about the senses of touch, taste, and smell in this discussion of the senses in the lower animals. These three senses have been so exhaustively treated by Lubbock in his Senses, Instincts, and Intelligences of Animals, that I could not hope to introduce any new data in regard to them. Graber, Frey, Leuckart, Farre, Hertwig, and a host of others have likewise investigated these senses most thoroughly.
As to the senses of sight and hearing, the matter presented a different aspect. I was confident that I could add somewhat to the knowledge already formulated, consequently I have treated these senses at some length. Technicalities and the details of microscopic investigation, especially microscopic anatomy, have been omitted; they have no place in a work like this.
FOOTNOTES:
[5] Vide the writer, N. Y. Medical Record, August 15, 1896.
[6] Semper, Animal Life, p. 83.
[7] Hickson, The Fauna of the Deep Sea, p. 150 et seq.
[8] Lubbock, Senses, Instincts, and Intelligence of Animals, p. 84.
[9] "In Solaster or Asteracanthion the lenses look like brilliant eggs, each in its own scarlet nest."—Lubbock, Senses, Instincts, and Intelligence of Animals, p. 132 et seq.
[10] Lubbock, loc. cit. ante, p. 140.