242 
HUMBLE-BEES. 
rich yellow ; when it grows old, especially the male, 
exchanges these brilliant colours for a cinereous hue, 
which circumstance misled Fabricius to give it as a 
distinct species, under the name of A. Senilis. But 
not only yellow and red, but even black and white 
hairs are apt to change their colours through age. 
All these circumstances make it a matter of some 
importance to be able to distinguish a recent insect 
from one that has been long disclosed. This may 
often be done by inspecting the state of its wings, 
for in the latter, especially in males, they are usually 
lacerate at the apex ; the body, too, has frequently 
a good deal of its hair rubbed off. It will not be 
without use to know into what the predominant 
colours fade ; yellow will usually first turn pale, and 
then cinereous ; red will turn through tawny to yel- 
low, and sometimes to cinereous ; white will turn to 
pale, and sometimes to tawny ; and black will now 
and then turn white. But this is not all the difficulty 
with which the describer of the Bombinatrices has 
to struggle ; the males in general resemble the fe- 
males sufficiently to be known as such ; hut there 
are several so unhke them as to be easily mistaken 
for different species ; and I am by no means certain 
that I have not, in more instances than one, described 
the sexes under different names. Till all can be 
traced to their nidi, this is not easily to be avoided.” 
We shall now proceed to give examples of tha 
two genera Bombus and Apathus. 
