877 
No. 145.] 
he darts backwards and wriggles about so suddenly and spitefully, 
it will be an interesting topic for some future observer to notice 
by what artifice his mortal fee induces him to remain quiet or is 
able to cling to him long enough to puncture and drop an egg 
within his skin. The knowledge and skill which these Ichneumon 
and other parasitic Hymenopters often show in- their proceedings 
is tiuly wonderful. Every person will recollect the larva of the 
Isabella tiger-moth (Jlrctia Isabella )—the large caterpillar with 
still' even-shorn hairs of a tan color and black at each end of his 
body, which crawls about our yards and often enters our dwell- 
ings—and will probably have observed the fact that if when 
crawling he is rudely touched he suddenly stops and doubles him¬ 
self together for a moment, and then straightens himself again 
and resumes his journey. The long stiff hairs with which he is 
protected much like a porcupine, we should think would render 
it impossible for an insect enemy to place an egg anywhere upon 
his skin. Mr. P. Reid tells me he once saw' one of these cater¬ 
pillars crawling with a hurried eager step across a dusty road, 
with an Ichneumon fly pursuing him, striving to cling upon his 
back, but falling off in consequence of the rapid motion of the 
caterpillar. The fly finding itself frustrated in its every effort, 
next, as if humming to itself the refrain “’Twill never do to give 
it up so,” flew r a tew feet forward of the caterpillar, and turning, 
darted back with all its energy, hitting the caterpillar square in 
his face. The caterpillar thus roughly assailed suddenly stopped 
and bent himself together in his accustomed manner, and in an 
instant the fly, alighting upon his back, appeared to fix an egg at 
the margin of one of the breathing pores, which had become fairly 
exposed by the caterpillar doubling his body thus together. In a 
moment the caterpillar was recovered from his shock and was 
crawling rapidly forward again, when the fly struck him a second 
time in the same way, and thus he was' stopped and had an egg 
deposited upon his side three times, before he reached the tall 
grass beside the highway, in which he was secure from further 
molestation. And it is probable that by some artifice equally 
curious and remarkable, the parasite of the Cabbage moth is able 
to drop an egg into the skin of his irritable, brisk motioned 
victim. 
