a few Observations in Mimicry. 3 
not often settle on flowers, but like the fossorial wasps settle 
on the ground, on a bank, or on a leaf, places identical 
with where the Pompilid wasp settles. As to whether 
such cases of mimicry are Batesian or Miillerian in their 
origin is probably not difficult of solution. It seems 
reasonable to suppose that the former is the explanation, 
for a powerful stinging wasp is not only unpalatable, but 
is actually dangerous to an attacking enemy, while the 
moth is harmless and must by comparison be even palatable. 
But Miillerian mimicry for its working presupposes ex- 
perimental attack on model and mimic alike. In such a 
case as a stinging hymenopteron for a model it is unlikely 
that experimental attacks could be numerous enough, 
if they occurred at all, to affect to any appreciable extent 
its numbers. As soon as the young bird was old enough 
and able to catch insects and feed itself would it not instine- 
tively leave wasps alone, seeing that all wasps can sting 
and to that extent at least be unpleasant ? Instinct is a 
real thing, which Lloyd Morgan has so pithily expressed 
as follows: “ Instinct depends on how the nervous system 
is built through heredity.” Now, with the lepidoptera as 
food for birds, instinct as to which are good and which are 
bad probably does not count to any appreciable extent. 
Experiences are varied and the nervous system is probably 
affected in a very complex fashion, so that anything definite 
is not transmitted by heredity, such as must be concerning 
the edibility of wasps. 
DETAILS OF THE INSECTS FIGURED. 
Fig. 1 represents T'richura grandis. This fine species 
was described by me after I had observed and taken it near 
Santos in February 1910. It flew and alighted just like 
a large wasp. The only specimen that I was able to catch 
was flying along a path in the forest, and several times I 
noted it settlng on the ground, and finally it was observed 
settled on a leaf vibrating its wings when it was taken. 
Unfortunately no wasp was taken that could be claimed 
to be its model, but at that time (Feb. 27th) the species 
was only just beginning to appear, as Mr. Dukinfield Jones 
took a series later on, but did not specially look for a model. 
The habits of several species of Trichura are identical in 
the manner of flying low down along a path and settling 
on the ground. At the same time and place 7. dixanthia 
was so observed, and the remarkable tail to the abdomen 
