78 
NATURAL HISTORY OF 
including the horns. The largest coleopterous insects 
inhabiting Britain are the Hydrous piceus, and the 
Stag-beetle ( Lucanus cervus ). The latter is nearly 
two inches in length, including the mandibles ; and 
the former is not much short of the same dimen- 
sions, besides being of considerably greater breadth. 
These may be regarded as the giants of this order 
of insects, occupying one extremity of the scale. 
At the opposite extremity may be placed some 
species of the genera Trichopteryx, Atomaria, and 
Agathidium, which are so minute as not to exceed 
one-eighth part of a line in length ;* or, to adopt 
an illustration sometimes employed, they are abso- 
lutely not bigger than the full stop that closes this 
period. 
The structure of these minute beings is perhaps 
even more calculated to excite our admiration than 
that of the larger animals. In the latter, most of 
the parts are of sufficient size to come within the 
direct cognisance of our senses, and there is no ap- 
parent discrepancy between their dimensions and 
the functions which they perform ; but -when we re- 
flect that a mere animated point, almost invisible to 
the naked eye, possesses all the attributes which be- 
long to the largest of its race — that it is furnished 
with an external covering made up of many parts 
adjusted to each other with the nicest accuracy — 
that it is supplied with all the requisite organs of 
A line is the twelfth part of a French inch. 
