428 THE GROUSE IN HEALTH AND IN DISEASE 



four of which form a curved row near the posterior margin, and the rest a row 

 near the anterior margin. In a dorsal view the head is quite invisible. The 

 meso- and meta-thoracic segments, and those of the abdomen, are each provided 

 with a row of four bristles, which are about equidistant from each other. 

 Laterally, below the level of the spiracles, the abdominal segments are each 

 tipped with a tiny bristle. Seen from beneath (see PI. LVIIL, Fig. 4) the pupa 

 shows distinctly the legs folded up close under the body, and the antennae 

 beautifully curled under the two anterior pairs of legs and brought out again 

 so as to show the tip of each close to the four anterior tarsi. Most of the joints 

 of the legs may be distinctly seen, the posterior pair being folded beneath the 

 wing-cases, which are bent round from the dorsal surface of the pupa and do 

 not nearly reach the end of its body. 



The first change to be noticed in the pupa is that on the fifth day after 

 emergence the eyes begin to change colour, assuming a pale brown tint, 

 while a couple of days later they are of a more distinct brown, and the 

 separate facets 'may be distinguished. On this day also (the seventh) the 

 extreme tips of the mandibles become darkened. Six days later the eyes 

 have become very dark brown, almost black, while the mandibles are of a 

 rich brown tint. When two more days have elapsed, i.e., on the fifteenth day of 

 pupal life, the tips of the mandibles are quite black, while the maxillae have 

 commenced to darken at the tip. On the seventeenth day the wing-cases, legs, 

 and antennae darken in colour, and the markings on the forehead, etc., characteristic 

 of the mature beetle, are plainly seen, while on the eighteenth day the changes 

 are fully accomplished, and the beetle emerges to enjoy a free and active existence. 

 The pupal stage thus lasts, in a typical case, about three weeks. 



The emergence of the beetle from the pupal skin commences with the 

 liberation of the legs from the body, and occupies, judging from an example 

 which I carefully watched, about four hours ; but the elytra (wing-cases) are 

 even at the end of that time quite pale, and only darken and harden quite 

 gradually, assuming their permanent condition several hours later. The 

 anterior legs and the antennae are the first appendages to become capable of 

 free movement, while the whole of the six legs are practically free in the 

 space of an hour. As the struggling movements proceed, it is easy to notice 

 the extreme thinness of the enclosing pupal membrane. It is apparently of 

 considerable toughness, but is ultimately ruptured by the vigorous, movements 

 of the limbs. 



