11 
in the expanse of the upper wings, and 3-J inches in the 
lower wings, and he mentions that the peculiar narrowing 
of the upper wings towards their apices is very singular. 
The Darwinian theory appears to he making progress 
among a certain class of naturalists, hut its upholders dis- 
play a disposition to avoid precision of terms, and to enlarge 
and confuse the meaning of the words they employ rather 
than scientifically to limit and define them; they use varia- 
bility and mutability as having one and the same meaning^ 
instead of distinguishing one as referring to subdivision into 
varieties, and the other as change of specific forms. Just 
now, as a development of the tlieoiy of natural selection, we 
hear a great deal from some distinguished entomologists 
about imitation and mimicry, where resemblance would be 
the more correct word; and these terms cannot be said to 
be used figuratively because it is argued that some species 
and genera of butterflies mimic the colourings and markings 
of others for the sake of protection from enemies, and for 
other aims and ends. Certainly the words imitation and 
mimicry imply foregone intention. Now it is probable that 
no butterfly ever saw its parent or ancestor, its offspring or 
posterity, and it is an absurd stretch of imagination that its 
own observation could induce and enable it to change the 
colouring and appearance of its successors; and if it had such 
ability and reasoning power it would effect the change for 
protection from enemies in the larva and not in the imago. 
We know that Nature loves to repeat her works, and it is 
common to find resemblances and repetitions through various 
and distantly allied families of animals, and they are truly 
connecting links in the chain of creation. 
The controversy is still going on between those who affirm 
and deny the existence of a vital principle of energy or force, 
and Professor Huxley stands foremost among the latter; 
very interesting microscopic observations have been made, 
and ingenious arguments have been deduced from them, but 
