14 
SEASONAL VARIATION 
Meanwhile the history of racial conflict and conquest will 
repeat itself. And its great paradox will not seldom also be 
repeated. As in the old world Greek slaves and Jewish outlaws 
proved stronger than their Roman conquerors, so in the future 
will races and their empires that rest on force be swayed and 
transformed by invulnerable revolutions of the mind. 
SEASONAL VARIATION WITH SPECIAL REEERENCE 
TO THE GENUS JUNONIA 
By the Rev. K. St. Aubyn Rogers, M.A., F.E.S. 
The subject of variation is a study of no little importance, 
inasmuch as it is probable that it will throw more light on the 
vast subject of the inception of new species than any other 
investigation. It, moreover, requires co-operation on a large 
scale because for its pursuit large numbers of specimens from 
properly authenticated localities and duly dated are necessary. 
Breeding on an extensive scale is of primary importance, and is 
sure to repay the trouble by the interest of the results obtained 
if carried on with due care. The butterflies especially are 
suitable for experiments of this nature, because they are so 
variable and are influenced by so many different conditions. 
Not only do the males and females show great differences in 
many cases, but most species of wide distribution show con- 
siderable, and in some cases large, amounts of variation in 
different geographical areas. It is, for instance, often possible 
to say at a glance whether specimens of many species have 
come from East or West Africa. In this case specimens which 
come from the districts where these two areas overlap are of the 
first importance. 
Then, again, in butterflies there are often marked differences 
between the specimens characteristic of the wet season and the 
dry season respectively, and these differences reach their highest 
development in Africa. Owing to the fact that our wet and 
dry seasons are not so well defined as in other parts of the 
continent, it may happen that one form does not occur at all 
