of chloroform, and destroys the con- 
sciousness o'f the caterpillar. But 
as every segment has a separate mo- 
tor-center, the caterpillar still kicks 
and struggles automatically, and there- 
fore the wasp perforates and paralyzes 
each pair of segmental ganglia, thus 
rendering the caterpillar quiescent 
and insensible without killing it, that 
it may keep fresh for lhe wasp mag- 
got until entirely devoured. 
It is important to distinguish the 
tent caterpillar from the Cottonwood 
web-worm, of which we shall proba- 
bly have something to say later on. 
This latter is much lighter in color, 
and the head is not grey. It spins 
extensive webs on the cottonwoods in 
eastern Custer county, and Fremont 
and Pueblo counties. 
THE BUTTERFLIES OF COLORADO. 
Nathalis iole. — A little pale yellow 
buttefly, which cannot be mistaken 
for any other, because it is so small, 
being not much more than an inch a- 
cross the wings. The tips of the fore 
wings are black, and there is a black 
patch near their lower mat gins; the 
hind wings are mostly yellow in the 
male, but shaded with dusky in the 
female, while in both sexes the por- 
tion of the hind wings overlapped by 
the fore wings is mostly occupied by 
a broad dash of black. In the males 
there is on this dash of black a much 
elongated spot, which is extremely 
interesting because of its peculiarities 
and our ignorance of its purpose, un- 
less it be an ornamentation of the 
male for the delectation of the other 
sex. This spot is in some specimens 
pale yellow, while in others it is or- 
ange, yet these latter, if killed and 
mtk kept in the cabinet, do not retain 
V ^ their orange spot; sooner or later it 
fades suddenly away, and becomes 
pale yellow, as it is in some specimens 
from the beginning. We supposed at 
first that all examples of Nathalis iole 
had this orange spot when alive, but 
we find this is not so, having obtained 
a variety in which the spot was yellow 
when the insect was caught. There- 
fore we have apparently an orange 
spotted form, which we will call au- 
reomaculata. evolving from a proba- 
bly more primitive yellow spotted 
type, flavomaculata; but the new 
combination of pigment, whatever it 
is, is not yet fixed, and will even break 
up suddenly into the old form long 
after the insect’s death. 
* 
Nathalis iole is at present only 
known to us in Colorado from two 
counties, Custer and Pueblo, but 
doubtless it will be discovered in oth- 
ers in course of time. 
NOTES. 
All observant people must have 
seen the yellow spiders that sit on 
yellow flowers, and white spiders that 
sit on white flower , and catch bees 
and other insects which visit the 
flowers not noticing their enemies be- 
cause of their deceptive coloring. 
These spiders live on their looks, and 
never go to the trouble of spinning 
any web. According to Mr. James 
Angus, the white and yellow spiders 
are the same species, and change col- 
or, chameleon-like, according to the 
flowei they find themselves on. We 
shall make experiments to test this 
statement when the summer comes 
round. 
Interesting Entomological speci- 
mens sometimes come to visit us on 
our imported fruits. At Westcliffe, 
we found the caterpillar of the cod- 
IS 
