LIFE-HISTORY OF THE HERB ROBERT 105 
the two together certainly suggest that it is not whole- 
some food for this caterpillar, but perhaps my first 
friend was out of health when I caught him. The 
other was a much younger and apparently a perfectly 
healthy individual. I gave him various leaves of 
other sorts for a few days, and then nothing but Herb 
Robert. He began upon it at once, and ate, as is the 
custom of caterpillars, a large amount daily for five 
weeks and two days. I gave him a few dead leaves 
among which to spin his cocoon, but to my great 
surprise he made not the least attempt to do so; he 
simply lay still and turned into a chrysalis without 
more ado, on the soil in the pot with which I had 
provided him. This chrysalis was evidently healthier 
than the other, for the moth appeared in due course. 
It was quite typical as regards both colour and pattern, 
but it was considerably smaller than usual, the length 
of the front wing being barely an inch, which is short 
even for the male, which is normally smaller than the 
female. ; 
Now, it is rather remarkable that, except for the 
Milk Slug, the larva of the Small Yellow-underwing 
and the second of the two Woolly-bears, either the 
living leaves were not eaten at all or the eaters came 
to a premature end, while the Woodlice seem to have 
perished from being shut up with them in the same 
box, and the Tiger Moth was undersized. All the 
same one must not attach too much weight to a few 
isolated experiments of this sort, and I do not feel 
inclined to say more than this: that they suggest 
that the leaves are protected from marauders by their 
secretions and glandular hairs and perhaps by their 
exhalations too. I am told that in some parts of the 
country the cottagers like the plant because they 
