Packard.] RELATIONS OF INSECTS TO MAN. 
87 
the skin. These gradually disappeared; those nearer the 
surface by a scaling of the skin above them; those deeper, 
removed by the slower process of absorption, were visible at 
least two weeks. When the larva was permitted to fall upon 
the thicker skin of the palm of the hand, a slight stinging 
sensation was experienced and minute purple dots were 
developed, continuing a shorter time than the above. 
“The sting is doubtless the result, not of broken tips of 
the spines remaining in the flesh—for none such could be 
observed by careful scrutiny with a lens — but of a poison 
secreted by the larva*, and probably injected through a mi¬ 
nute aperture in the tip of the spine. Whether its excretion 
is voluntary or involuntary was not determined, it not 
having occurred to institute the simple experiment by which 
that point could readily have been ascertained. A slight 
motion of the larva, apparently a contractile one, was fre¬ 
quently observed to accompany the sting ; but this may have 
been either defensive, or simply the consequence of alarm at 
being rudely touched. 
“Some tips of the spines clipped off and placed between 
slides under a high magnifying power, showed, under varying 
pressure, a motion of fluid within them; but no apical 
opening could be discovered for its escape. 
“The ability to inflict a sting does not belong to all the 
spines of the larva, but only to those of the two subdorsal 
rows on segments three to ten, and the dorsal spine on seg¬ 
ment eleven. These differ from those elsewhere on the body 
in their fascicular arrangement, their lesser length, the 
regular taper of the branches, and their tawny color, as ap¬ 
pears in detail in the description given of the mature larva. 
With this interesting structural peculiarity in mind, the larva 
may be handled with impunity, as was repeatedly done with 
the fifty or more individuals composing the colony from which 
these notes were drawn, in the frequent transfers, which they 
♦That a poison is secreted seems to us improbable.—A. S. P. 
23 
