No important popular books on butterflies have appeared in recent years. The best single work for the general reader is still Holland’s _Butterfly Book_; those living west of the Rockies should have Wright’s _West Coast Butterflies_ also. CHAPTER II THE BUTTERFLY’S BODY The body of a butterfly, like that of any other insect, is divided by constrictions into three parts: the head, the thorax, and the abdomen. The head carries the eyes, antennae, and mouth parts; the thorax bears the legs and wings; and the abdomen the sexual appendages. THE HEAD, EYES, AND MOUTH PARTS The _head_ is globular, usually a little flattened from front to rear. Two large _compound eyes_ are located at the sides of the head, and the face or front consists largely of a plate called the _clypeus_. Above the clypeus and between the eyes are the _antennae_ or feelers, which are believed to be the organs of hearing, smell, and touch. Below the clypeus is the _labrum_ or upper lip, and the rudimentary _mandibles_; just below these are the two _maxillae_, which unite to form a tube called the _proboscis_, used in sucking nectar out of flowers. When not in use the proboscis is coiled up like a watch-spring between the two three-jointed _labial palpi_. The _labium_ or lower lip is very small in butterflies. THE THORAX, WINGS AND LEGS The _thorax_ is composed of three segments, the front part or prothorax, the middle part or mesothorax, and the hind part or metathorax. The _prothorax_ bears the front legs; the _mesothorax_ the second pair of legs and the fore wings; the _metathorax_ carries the third pair of legs and the hind wings. The under side of the thorax is called the _pectus_ or breast. The large muscles which operate the legs and wings are contained in the thorax. One pair of _spiracles_ or breathing-holes is found in the prothorax; the other seven pairs are located in the abdominal segments.