Butterflies and Moths. 15 



between the two. There is also another interesting distinction, 

 which is not, however, so well known. It is this: — 



On the anterior or front margin of a butterfly's hind-wing there 

 is a vein running out close to the body from the anterior vein of 

 the three principal ones in the wing. This vein supjiorts a piece 

 of the membrane or tissue of the wing, and being in a different 

 plane from that part of the wing, necessarily elevates that part of 

 the membrane that is nearest it to a slightly slanting position. 

 This slanting part moves during the motion of the wings in a small 

 hollow on the underside of the front wing thus partially locking the 

 two together. 



In n)oths it is different. Instead of a vein supporting a portion 

 of membrane, we have a strong pliable bristle in exactly the same 

 position running out from the wing, which bristle fits into a little 

 loop or groove on the front side of the front wing ; thus joining the 

 two strongly together. 



There is again another difference in the habits of butterflies 

 and moths. For while all butterflies repose with their wings 

 upright, most moths repose with them spread out or else with the 

 hind wing gathered up under the front, which is brought alongside 

 of the body. 



As a last difference I shall adduce that of the number of broods 

 of butterflies and moths in the year. 



Except in very few instances moths have not more than one 

 brood a year, nor again do they hybernate in their perfect state 

 through the winter, though there are some winter moths ; butter- 

 flies on the other hand have often two, and in very warm seasons 

 three broods a year, and hybernate especially when in a warm 

 spot. 



It is a curious fact that the eggs and pupae of butterflies and 

 moths will live in the most intense extremes of heat and cold, and 

 that butterflies do not require the summer to draw them from their 

 chrysalides, but will emerge in a hothouse even in the depth of 

 winter. 



In the conversation which ensued the President observed that 

 Mr. Bates, in his " Naturalist on the Amazons," had pointed out 

 the immense importance of the study of butterflies for the purpose 

 of observing the limits of species, and the changes to which they 

 are liable in consequence of local influences ; since all the super- 

 ficial signs of change in their organization are, as it were, exagge- 

 rated, and made unusually. plain by aflecting the shape, colour, etc., 

 of the wings, which many anatomists believe to be extensions of 



