Having, then, pointed out, as clearly as my limited knowledge of the subject will permit, not only the principal contents of the class Lepidoptera, but endeavoured to establish them in appointed and fixed stations, and to show their mutual approaches, at least those of the most striking kind and essential to my purpose, I must now proceed to make a few remarks on the nature of these approaches. It will be observed, that they are, almost without an exception, what Mr. MacLeay considers relations of affinity, that is, the relation is between species which, in their imago state, have a real and positive similarity to each other; so much so, that entomologists, unacquainted with the prior states, and frequently even in direct defiance of their own knowledge of those states, place them in orders, and even sub-classes to which they do not belong; to which fact all our systems and catalogues bear most ample testimony. This similarity is by no means confined to a cursory glance at the insects, but bears the test of a minute anatomical investigation, the antlia, palpi and antennæ demonstrating the approach quite as forcibly as the form and appearance of the whole insect. Where a tribe has short biarticulate palpi, a genus departing from the type will assume elongated and triarticulate palpi, should another tribe with those characters approach it: again, should a tribe with long antlia approach a tribe whose character it is to have none, we shall be sure to find a genus without antlia at the point of approach. On the other hand, the very egg, the larva, the pupa, the mode of feeding and description of food, the mode of metamorphosis, and, in fact, every prior quality, or state, from which distinctions could be obtained, differ so decidedly, that the characters of these often bear as near an approach to those of Hymenoptera, Neuroptera, and even Coleoptera, as to those of their own kindred, into immediate contact with which these approaches will be found inevitably to bring them. What term can then be applied to designate the real value of this species of approach? Supposing the terms analogy and affinity to have had good, sound, and distinct meanings, as originally employed and explained by great naturalists, they have now been so confused, confounded, and utterly misunderstood by ignorant persons, that either of these terms is entirely out of the question:[54] in fact, a suitable term by which to designate this peculiar species of relation or approach, I neither know where to find, or how to invent; and, therefore, I shall purpose simply to call it relation of larva, relation of pupa, or relation of imago, as the case may be.