288 



ORTHOPTERA 



third ecdysis occurs in six or eight days after the second ; the 

 rose colour becomes more distinct, and the head is of a brown tint 

 instead of black. After eight days the fourth ecdysis occurs ; 

 the creature is then about 3 5 millimetres long ; its colour has 

 much changed, the position of the markings is the same, but the 

 rose colour is replaced by citron yellow, the line of the spiracles 

 is marked with white, and at this time the creature has the " first 

 rudiments of wings," and is very voracious. In ten days another 

 ecdysis takes place, the yellow colour is more vivid, the prothorax 

 is definitely speckled with white, and the hind body is increasing 



FIG. 174. Development of wings in Caloptenus spretus : the upper row gives a lateral 

 view of the thoracic segments, and the lower row a dorsal view of these segments ; 

 1, second instar ; 2, third instar ; 3, fourth iiistar ; 4, fifth instar. (After Riley.) 

 t, tegmen ; w, wing. 



much in size. In fifteen or twenty days the sixth moult occurs, 

 and the Insect appears in its perfect form ; the large tegmina 

 now present are marked with black in the manner so well known, 

 and the surface generally is variegated with bluish and rosy marks. 

 Although this is the colour in Algeria, yet apparently it is not 

 so farther south ; the Insects that arrive thence in the French 

 colony are on some occasions of a different colour, viz. reddish or 

 yellowish, those of this latter tint being, it is believed, older 

 specimens of the reddish kind. M. Brongniart points out that 

 some Phasmidae of the Phyllium group undergo an analogous 

 series of colour-changes in the course of the individual develop- 

 ment, though other species do not. 



