Holmesdale Natural History Club. if 



closing behind, gives no clue that they have gone. One species only has a 

 different habit, C. Conyzffi ; this bites off the end of the case to render after 

 emergence easier. In some of the Tineina the case or cocoon makers simul- 

 taneously extrude the pupa from the coeoon and the imago from its- 

 envelope ; but the Nepticula thrusts half its pupa through the cocoon before 

 it begins to split for the exclusion of the perfect insect. The Elachistidsa, 

 suspended on the leaf by a thread, can scarcely be known to have yielded 

 up the perfect insect excepting by the transparent pupa shell. What a- 

 contrast to Hip. Semele, -which smashes up the case thoroughly, and scatters- 

 it in five or sis fragments on the surface I The Pterophori pupfe, although' 

 attached by the posterior segment, jerk themselves about in a strange' 

 manner; and some of them, previous to the imago emerging, are adorned 

 with iridescent markings, reminding one in a slight degree of the Vanessidse, 

 ■whilst the red shell of Dominula gives an appearance to the inmate very 

 much at variance -with its natural coloration. 



Having now shortly touched upon the emergence of the perfect insect, 

 and the appearances set up in the pupa prior to the last stage of life being 

 assumed, I must say a few words on the phenomena of the wing develop- 

 ment previous to flight. The growth and expansion of the wings from the 

 embryo till the time when the insect rests for the necessary hardening pro- 

 cess previous to flight is o-wing to the distribution of at least two distinct 

 fluids ejected from the body of the insect through the arteries and veins, 

 which in their turn, after having fulfilled the offices they were primarily 

 intended for, contract, condense, and anastomose into radial bones with 

 basal muscles for adhesion and flight. These fluids are not projected at 

 first together, but appear to be evolved and distributed in turn ; that one 

 that produces colour or pigment has already been in use for some time 

 previous to the insect's emerging from the pupa. It is therefore for a 

 time suspended in its flow, whilst the other is employed for the perfection 

 of the wing ; this is the period of growth that begins a short time after a 

 suitable resting-place has been occupied by the insect. If now disturbed, 

 the action is suspended or withheld, and a cripjDle is the result; cases, too, 

 have been recorded where the growing power has been withdrawn altogether 

 and the conditions reversed, so that the vrings diminished in size instead of 

 increased. The differing rumpled appearance of the wings in various 

 species during growth is caused by the position of the wing rays, which 

 ■will be readUy understood by referring to the diagram wing map in 

 Wilkinson's " British Tortrices ." Its explanation is simple. The circulation 

 through the posterior channels is a work of some time, whilst the flow to 

 the centre of the -wing is greater than the small passages can for a time 

 carry away ; hence in many species a bursting of the conduits would take 

 place were it not for a bag or sac situated on the disc at the spot of junc- 

 tion which receives the fluid and prevents such a catastrophe. Nature, 

 whose vagaries we so much delight in, in some foreign species places a 

 pocket-like receptacle outside also, but in British insects this is confined to 

 one, the curious Yinula, in which it can be distinctly seen whilst the insect 



