420 THE ZOOLOGIST. 
down to the most casual intruder, there are many steps and 
divisions which connect them with, or separate them from, each 
other. Some of these steps teach us, I believe, how the more 
perfect types in each group have been evolved in nature. For 
example, a beetle which is often found with ants, but more 
generally elsewhere, may show us how the first steps were taken 
to become more fully or exclusively myrmecophilous. It may be 
regarded to represent an ancestral form, not of any particular 
species, but of the commencement of the habit of being a myrme- 
cophilous insect, as it is quite certain that the inhabitants of 
ants’ nests must have been evolved long after the ants them- 
selves. If, therefore, a species is often found with ants, and 
often with the same species of ant, although more generally 
found away from them, it is quite clear that it is not there by 
chance. I think it is wrong to say it has nothing to do with 
them, but rather to regard it as a case in point of the question I 
have just raised. We should try and find out what it is doing in 
such situations, a situation, moreover, of considerable danger to 
a perfectly non-myrmecophilous species. The above remarks 
apply to spiders as well as to all other creatures found with 
ants. I would divide the myrmecophilous spiders into three 
groups :— 
I. Those species which are always found with ants. They 
belong to the indifferently tolerated lodgers. 
II. Those species which hunt and prey on ants. They are 
generally found outside and in the neighbourhood of the nests. 
III. Those species which closely resemble ants in appearance. 
They hunt their prey in the neighbourhood of ants’ nests, and 
are protected from outside enemies by their resemblance to ants. 
It is very difficult to classify exactly species into these diffe- 
rent groups without further evidence on their habits. Finally, 
there are a number of spiders which I have found singly in ants’: 
nests, whose occurrence there may be accidental. They may in 
some cases have been carried into the nests by the ants and not 
devoured, or have sought the nests for the reasons given by 
Mr. Cambridge. But even in this latter case they may be the 
first steps towards a myrmecophilous habit. I may here quote 
with advantage a ‘passage from one of Prof. Wheeler’s publica- 
tions :—“‘ In the lives of the social insects the threptic or philo- 
