L'O 



centre of tlie back of the larva, being at first darkish, but gradually 

 turned to a faint red ; after a brief interval, tbe markings of its 

 head were thrown off from the front, and not permitted to recede 

 down the body of the larva as the old skin had done. The body of the 

 larva was then quite white and spotless, and the whole of the dorsal vessel 

 slowly assumed a pale reddish tinge, the larva in the meantime laying 

 motionless, the tip of its mouth gradually assuming a reddish brown 

 tint, and down the centre of its head two pale brown parallel lines made 

 their appearance ; its head then became brown, and shortly afterwards 

 a dark triangular patch appeared on each side thereof ; at this stage of 

 its economy the larva resumed its feeding, and then the dorsal vessel 

 becoming green, imparted a greenish tint to its body ; the larva con- 

 tinued feeding till the 3rd of May, when becoming full fed, its head was 

 brown, body white, and the dorsal vessel became invisible ; it then 

 retired under the mould in the breeding cage and spun its cocoon — 

 "Frass" sap green, afterwards turns black. 



The observation of the aj^pearance, disappearance, and re-appear- 

 ance, either partial or wholly, and the change of colour in the dorsal 

 vessel of this and other micro-lepidopterous larva have been to me a 

 subject of most interesting study. In May, 1863, I discovered a larva 

 belonging to this genus feeding in the leaves of Gastanea vulgaris 

 (Spanish chesnut), the dorsal vessel of which larva when full fed had 

 a most remarkable appearance, being at one time faint gi-een anteriorly, 

 pale orange in the centre, and dark green posteriorly. I have repeatedly 

 noticed that the larvae of this genus exhibit signs of great uneasiness if 

 held before a lighted lamp or candle, when they lash and wriggle their 

 bodies about all over their mines, and endeavour by every means in 

 tlieir power to escape from the object that causes them so much terror. 



When the time has arrived for the imago to make its appearance, it 

 issues forth from one eud of its cocoon, and lying on its back (this I 

 have found to be invariably the case), the pupa skin cracks at the back 

 of the head, from whence the imago gently slides out about a third of 

 its length, its abdomen is then very soft, and has a slight hyaline 

 appearance, after an interval of several minutes it slides out a little 

 further, its abdomen then becomes slightly darker, it again takes another 

 short rest, when presently a slight quivering of the palpi is observable, 

 this is directly followed by a corresponding movement of one of the 

 legs (sometimes these movements of palpi and legs take place a second 

 time), when almost immediately afterwards it stretches out its legs and 

 antennae, and springing over on to its feet, hurries up the side of the 

 breeding cage, and curving in its body, stretches out its wings to dry. 

 Its pupa skin is left projecting from the cocoon, and if the same be 

 drawn gently out, the skin that the larva threw off just previous to 

 entering the pupa state will be found slightly adhering to it. 



