52 
rOPULAR SCIENCE REVIEW. 
NOTES ON BUTTERFLIES. 
Br the Rev. C. HOPE-ROBERTSON, F.R.M.S. 
[PLATE LXIX.] 
T HESE lovely creatures give as much pleasure to the student 
of science as to the child at play, who runs, cap in hand, 
to chase them. Their colours, forms, and habits, all furnish 
charming subjects for observation. We propose to collect some 
notes taken at intervals on these points, and show the methods 
available for easily exhibiting their interesting peculiarities. 
We begin with the distinction which serves, in general, to 
divide butterflies from moths, which is the existence of a club- 
shaped end to the antennae of the butterfly ; while the moth 
has sharp-pointed or plumed antennae. From this club-shaped 
end comes the generic word Rhopalocera , compounded of the 
two Grreek words for a club and horn . Observation has found 
this distinction characteristic of the butterfly tribe ; we wish 
further to see what there is in the habits of the creatures to 
explain the reason why they have such horns. 
If we look at one on a bright sunny day we will see its 
horns erect, stretched out, delighting in the sunshine. While, 
if we look at a moth, which flies chiefly at dusky hours, when 
it is brought to the light its horns are folded back, and doubled 
as far as possible under shade of its body or wings, as if unable 
to bear the glare. They are evidently most sensitive to light. 
Now this is a key to one purpose which the horns serve. 
They are the thermometers of these little weather-watchers. 
The degree of warmth needed for them is made known by the 
effect of light on the delicate tips of their horns or feelers. A 
club-shaped feeler gives a larger surface for the light to act 
upon ; and the nervous energy needed for the butterfly to 
enable its muscles to work, is collected by the club-shaped 
points, and its general influence stored up to sustain flight 
against the effect of a chill. Cold would paralyse them. Now 
if we take the microscope to examine the structure of the club- 
points, these are found to be full of cells, or depressions, where 
the heat and electric energy, accompanying light, may be 
