XIV INTRODUCTORY. 



are covered with exquisitely fine hairs. It is thought by some 

 that the senses of hearing and smell are lodged in the antenna?, 

 these organs thus combining the sense of feeling with those of 

 hearing and smelling. And the researches of anatomists lend 

 much probability to the assertion, since little pits just under 

 the skin are found, and even sometimes, provided with grains 

 of sand in the so-called ear of the lobster, etc., corresponding 

 to the ear bones of the higher animals, the pits being con- 

 nected with nerves leading to the brain. We have detected 

 similar pits in the under side of the palpi of the Perla. It seems 

 not improbable that these are organs of smell, and placed 

 in that part of the appendage nearest the mouth, so as to enable 

 the insect to select its proper food by its odor. Similar organs 

 exist on the caudal appendages of a kind of fly (Chrysopila), 

 while the long, many-jointed caudal filaments of the cockroach 

 are each provided with nearly a hundred of these little pits, 

 which seem to be so many noses. Thus Lespes, a Swiss anato- 

 mist, in his remarks on the auditory sacs, which he says are 

 found in the antennte of nearly all insects, declares that as we 

 have in insects compound eyes, so we have compound ears. 

 We might add that in the abdominal appendage of the cock- 

 roach we have a compound nose, while in the feelers of tlie 

 Perla, and the caudal appendage of the Chrysopila, the "nose" 

 is simple. We might also refer here to Siebold's discovery of 

 ears at the base of the abdomen of some, and in the forelegs of 

 other kinds, of grasshoppers. Thus we need not be surprised 

 at finding ears and noses scattered, as it were, sometimes 

 almost wantonly over the bodies of insects (in many worms the 

 eyes are found all over the body), while in man and his allies, 

 from the monkey down to the fish, the ears and nose invariabl}' 

 retain the same relative place in the head. 



How Insects Grow. When beginning our entomological studies 

 no fact seemed more astonishing to our boyish mind than the 

 thought that the little flies and midges were not the sons and 



