By examining a butterfly's head through a lens it is easy to see the principal appendages which it bears. Projecting forward from the middle of the top is a pair of long feelers or antennae. Each of these consists of short joints which in general may be divided into three groups: first, a few large joints at the base connecting the feeler with the head; second, many rather small joints which make up the principal length; third, several larger joints which make up the outer part or "club" of the antennae. In the case of the Skippers, there are in addition a number of small joints coming to a sharp point at the end of the club. Just below the insertion of the antennae on each side of the head are the large compound eyes, which are almost hemispherical. With a powerful glass, one can see the honeycomb-like facets, of which there are thousands, making up each eye. Just below the eyes there are two hairy projections, called the palpi, between which is the coiled tongue or sucking tube. (_See plate, page 64-65._) [Illustration: Butterfly Antennae, magnified. (From Holland)] Anatomically the thorax is divided into three parts--the prothorax, the mesathorax, and the metathorax; but the lines of division between these parts are not easily seen without denuding the skin of its hairy covering. The prothorax bears the first pair of legs. The mesathorax bears the front pair of wings and the second pair of legs. The metathorax bears the hind pair of wings and the third pair of legs. In many butterflies, the first pair of legs are so reduced in size that they are not used in walking. The abdomen is composed of eight or nine distinct rings or segments, most of which have two spiracles or breathing pores, one on each side. It also bears upon the end of the body the ovipositor of the female or the clasping organs of the male. BUTTERFLY TRANSFORMATIONS The butterflies furnish the best known examples of insect transformations. The change from the egg to the caterpillar or larva, from the caterpillar to the pupa or chrysalis, and from the chrysalis to the butterfly or imago is doubtless the most generally known fact concerning the life histories of insects. It is a typical example of what are called complete transformations as distinguished from the manner of growth of grasshoppers, crickets, and many other insects in which the young that hatches from the egg bears a general resemblance to the adult and in which there is no quiet chrysalis stage when the little creature is unable to eat or to move about. [Illustration: Egg of Baltimore Butterfly, much magnified. (From Holland)] _The Growth of the Caterpillars_