I02 TRUE TALES OF THE INSECTS. 



white, and with a rosy streak on each side of the hind 

 body. Generally six or eight days later the third 

 ecdysis takes place ; the general tint being the same, 

 but the rose colour becomes more distinct. After eight 

 days the fourth moult occurs ; when the creature should 

 be considered no longer a larva, but a nymph, for it 

 has the first rudiments of wings ; the position of the 

 markings is the same, but the rose colour is altered to 

 a citron yellow, and the line of the spiracles is marked 

 with white. In ten days another moult is undergone, 

 there is considerable increase in size, the yellow is 

 brighter, and the prothorax more definitely speckled 

 with white. In fifteen or twenty days the sixth ecdysis 

 occurs, and the locust enters the perfect state. The 

 large tegmina now present are marked with black, and 

 the surface generally is rosy and bluish. Such is the 

 colour in Algeria ; yet sometimes the insects arrive from 

 the South in the French colony reddish or yellowish 

 in colour, those of the latter tint being, it is believed, 

 older specimens of the red kind. We may recall an 

 analogous series of colour-changes in the course of the 

 individual development of some Phasmidse — of the 

 Phyllium group. 



The fact of these changes of colour in Orthoptera 

 during metamorphoses, and even after they have 

 become adult, is important, not only from a physiological 

 point of view, but as helping towards the determination 



