SCIENTIFIC NOTES. 101 



the case it is in contradiction to what both of two authorities say, when, 

 on p. 7, it is said that " H. virescens and H. riibroviridans may readily 

 become so." 



The natives are said to eat the plants, which when fresh, have the 

 flavour of a nut, and also use them when burnt, as colouring matter for 

 their tatooing, rubbing the powder into the wounds, in which state it has 

 a strong animal smell. 



The New Zealand name for this plant caterpillar \?,^^ ffotete" 

 " mveto.'" "Wen''' "• annhe." — J. Herbert Stott, 63, Manchester 

 Road, Bolton. [The parasitic fungus, mentioned by Mr. Stott as 

 Torriihia, is now generally known as Cordyceps, and belongs to the 

 Ascomycetes. Several species of Isaria, formerly placed in a quite 

 distinct genus, have been found to be simply a phase in the " alternation 

 of generations " which ends in the ultimate production of Cordyceps. 

 In the Journal of Microscopy , 1890, pp. 73-82, is a most interesting 

 paper on "The parasitic fungi of insects," by G. Norman, M.R.C.S., 

 with plates, in which the writer refers to a Cordyceps which has a New 

 Zealand larva for a host, but this species is called C taylori, I would 

 also direct attention to the Ejitomologisfs Record, vol. i., p. 267, where 

 similar larvae are mentioned. — Ed.] 



Wing Expansion. — Has it ever been noticed how much more 

 rapidly the wings of most diurnal lepidoptera expand than those of 

 truly nocturnal-flying species ? It is true that the former frequently 

 place themselves in such a situation that the rays of the sun fall directly 

 upon them while expanding their wings, which is rarely the case with 

 the others, but this cannot be the only solution. The idea of investi- 

 gating the cause of expansion of the wings of lepidoptera is a good one, 

 and might easily be settled, as far as evaporation or coagulation is con- 

 cerned, b) any competent microscopist. Coagulation, I should say, 

 can hardly be the cause, as the result would not be uniform, and I 

 doubt much if evaporation either has anything to do with it. My 

 reason for this is as follows : The wing of any lepidopterous insect is 

 composed of two membranes, supported on a framework of nervures. 

 That this is the case has been proved conclusively; for I recollect, a 

 few months ago, Mr. Waterhouse exhibited, at the Entomological 

 Society of London, a wing of one of the large American Saiurnidce (I 

 am writing from memory), which he had successfully split into two, or 

 divided the upper from the lower surface. Had the space between 

 these two surfaces been expanded by a liquid, which coagulated or 

 dried on the completion of the expansion of the wings, I should think 

 that such an operation would have been absolutely impossible. But 

 there is no objection to the theory that the expansion may be caused 

 by an injection of liquid into the hollow nervures, causing them to 

 stretch to their full extent and carrying the membranes with them. 

 The excess of the liquid is probably the opaque drop which is after 

 expansion, never before, exuded by the insect. I merely suggest this 

 as my own idea, but as I am not a practical physiologist, I daresay Dr. 

 Buckell can tell us if this be possible. — C. Fenn, Lee. Aprils 1891. 



Physiology of Expansion. — No one but Mr. Fenn seems to have 

 tackled this question ; — (i) As to ex])ansion. The unexpanded wing is 

 a miniatuie of the expanded. Newman, at p. 14 of British Buiterjiies, 

 quotes from Kirhy and Spence to the effect that the two membranes of 



