6 THE COMMONER BUTTEHFLIES. 



divisions, such as thimble-, sugar-loaf-, flask-, or acorn- 

 shaped, or even fusiform; others are globular, or hemi- 

 spherical, or tiarate. The surface may be more or less 

 deeply pitted, or delicately reticulate, or broken up by ver- 

 tical ribs connected by raised cross lines, or may be per- 

 fectly smooth and uniform; but all have a collection of 

 microscopic cells at the centre of the summit perforated 

 by little pores, formiug the micropyle, through which the 

 Qgg is fertilized; and these microscopic parts are often of 

 exceeding beauty. 



4. What the Oatekpillak is like. 



Caterpillars of butterflies do not differ from those of 

 moths by any single characteristic. Each family of Lepi- 

 doptera has certain peculiarities, and one has to become 

 more or less familiar with them to determine whether or 

 not a given kind falls in this or that family. 



They are worm-like creatures, but with a distinct horny 

 head, separable from the body. 



The head is very different from that of the future but- 

 terfly, having biting jaws, no compound eyes, but in their 

 place a semicirclet of simple ocelli, and antennae hardly 

 visible without a glass; these last, indeed, are very like the 

 palpi, a series of two to four rapidly-dimiuishing rounded 

 joints ending in a bristle. 



The body is composed of thirteen (apparently twelve) 

 segments of which the first three, corresponding to the 

 joints of the future thorax, have each a pair of horny five- 

 jointed legs ending with a single claw; while the third to 

 sixth and last abdominal segments bear each a pair of two- 

 jointed fleshy "prolegs," armed at tip with a single or 

 double series of minute booklets. Breathing pores or 

 spiracles are found on the sides of the first thoracic and 

 the first eight abdominal segments. Besides this, the whole 



