HEREDITY IN LEPIDOPTERA. 
195 
numerous species of Lepidoptera have caused the development 
of some remarkable phases of variation. By closely observing 
these phenomena for many years, it has of late thrown much 
light on the origin and development of several of our local 
species and varieties. Mr. Tutt, in his papers on Melanism, 
etc., has dwelt at length on the effects of certain localities in 
darkening British Lepidoptera, but, so far, that gentleman’s 
efforts have been directed towards an explanation of the causes 
producing melanism only. When we study the subject in the 
opposite direction, we just as easily reach conclusions (in their 
bearing as the case may be) in the development of brighter 
and paler colours. The sub-family SatyrincB comprise the 
blackest species of known Rhopalocera. They also constitute 
the second group in Bates’ Structural Classification of Butterflies, 
and considering the colours and low structure of the group, 
they were, doubtless, among the first to appear in early geolo- 
gical times. I am inclined to regard black as the primary 
colour of Lepidoptera, and the one most suited to the cool, 
wet climates of the ages through which they have passed. 
The evolution of the numerous species constituting the group, 
or of the higher groups from the Satyrince, need not be dis- 
cussed here ; we have sufficient evidence of their great 
antiquity and of several species still retaining their primary 
colour from their zone of origin through geological time ; it is, 
therefore, not difficult to understand how, under the ever- 
changing conditions and rapid modification of climates in 
modern times, numerous species should develop a tendency to 
vary in a given direction. The hereditary tendency to vary is 
more strongly marked in some groups than others, but I agree 
with Mr. Tutt in laying stress on this as an important factor in 
the production (under certain conditions) of Melanism, and it 
seems to me that we must take a much wider grasp of the 
subject than we have been accustomed to do when dealing 
with these important problems. The law of heredity among 
insects is comparatively unknown to entomologists, and until 
the science is perfectly studied very little sound progress will 
be made in developing our knowledge of the laws of variation. 
The thought has frequently occurred to me that the peculiar 
and beautiful variation of certain groups or species operates 
more from within than without. It seems to me not to be the 
mere external influences of artificial environment that produce 
the variation (useful or otherwise) in a bred species, but to be 
due to the law of heredity operating in a given direction. It 
