Note 48 — PART I.—MORPHOLOGY AND PHYSIOLOGY (continued 7)

In 1870 I observed these sense-pits in the antennæ and also in the cercopoda of the cockroach (Periplaneta americana). I counted about 90 pits on each cercus. They are much larger and much more numerous than similar pits in the antennæ of the same insect. I compared them to similar pits in the antennæ of the carrion-beetles, and argued that they were organs rather of the smelling than hearing. (Amer. Nat., iv., Dec. 1870.) Organs of smell in the flies (Chrysopila) and in the palpi, both labial and maxillary, of Perla were described in the same journal (Fig. 270). Compare Vom Rath’s account of the organs in the cercopods of Acheta (Fig. 271); also the singular organ discovered by him on the end of the palpus of butterflies, in which a number of hair-like rods (sh) are seated on branches of a common nerve (n, Fig. 272).