30 
[Jul]' 
tenements full of " frase." T handled sundry specimens of this lam 
before they were full-fed, and noticed no particular odour ; but when} 
happened to take up with my finger a full-fed larva, which I had 
watched tumbling down, I immediately dropped it in disgust, as a moBi 
unpleasant odour, similar to that of AcantJiia lectularia, struck my 
olfactory nerves.* 
The larvae now bury about an inch under ground, and pass thei) 
metamorphosis there in a spun stout cocoon of brown silk (not mixed wit! 
any earthy particles) , and of about the size of a grain of wheat. Mam 
of the cocoons having been attached to small pebbles, presented, afte'i 
removal, one or more flattened sides. When the cocoon is finished 
the larvae have completely lost the ofiensive odour they previoualv 
possessed ; I repeatedly made sure of this by turning larv^ out of thei" 
cocoons and purposely irritating them ; and at the risk of being de 
nounced as " dealing with hypotheses," I am tempted to conclude tha 
this odour is given to them as a safeguard during that short but mos 
critical moment of their lives, when neither the shell of the gall uo 
mother Earth can protect them againstiheir enemies. 
The imagos made their appearance between the 13th and I5t] 
October of the same year. On the evening of the last-named day, at ; 
quarter-past six, I began to watch one of the cocoons, which, by sundr; 
Blight movements, had given me warning of some impending change 
I had previously taken the precaution of placing several cocoons upoi 
a highly -polished glass. A few minutes afterwards the antenna of th, 
insect were gently pushed through a very narrow slit at the upper en( 
of the cocoon, and, with a tremulous motion, they seemed to explor. 
the surrounding spot; five minutes later a part of the forehead madr 
its appearance, and I could now see how the little busy jaws worke( 
their way along the slit mentioned, gradually widening it, until the toj 
of the cocoon, shaped like a skull-cap, was nearly detached. The insec 
directly pushed this easily aside, rapidly walking out of the cocoon, anc 
now busily cleaning its antenna by moving the fore-feet over them, anc 
subjecting the wings to the same process with the hind legs. It tool 
to flight immediately afterwards, and must have attained to full ma. 
{n«f„n.°'\v ^"°""*5, °/ *''*^ faculty being possessed by larvEe of saw^e7are on record • see fo 
instance \Vestwood, Introduction to Mod. CIhss. of Insects, vol. ii, p. lot Some VederasTwel 
Thriarirus* Sot'eX'e ufoneni "■^^'"'' '^^ "^'.^ '"^""'' °'"^^« "^^ coUred^ithHi J/S.^n ,1 
inese >ariou.s piotecliTe properties may possiblv, to some extent, account for the Tenthredlnida-hS^ai 
