of the stings is protruded below its point, as in the act of stinging; the other is free to show its form.  Now the actual length of this scabbard in nature was the one-thirtieth of an inch.  I have taken the point, C, of a fine cambric sewing needle, and broken it off to slightly less than the one-thirtieth of an inch, and magnified it as the sting is magnified.  Now here we obtain an instance of what I mean by magnification.  The needle point is not merely bigger, unsuspected details start into view.  The sting is not simply enlarged, but all its structure is revealed.  Nor can we fail to note that the finish of art differs from that of nature.  The homogeneous gloss of the needle disappears under the fierce scrutiny of the lens, and its delicate point becomes furrowed and riven.  But Nature’s finish reveals no flaw, it remains perfect to the last.

[Footnote 3:  A magnified image of the bee’s sting was projected on the screen.]

We may readily amplify this.  The butterflies and moths of our native lands we all know; most of us have seen their minute eggs.  Many are quite visible to the unaided eye; others are extremely minute.  A gives the egg of the small white butterfly;[4] B, that of the small tortoiseshell; C, that of the waved umber moth; D, that of the thorn moth; E, that of the shark moth; at F we have the delicate egg of the small emerald butterfly, and at G an American skipper; and finally, at H, the egg of a moth known as mania maura.  In all this you see a delicacy of symmetry, structure, and carving, not accessible to the eye, but clearly unfolded.  We may, from our general knowledge, form a correct notion of the average relation in size existing between butterflies and their eggs; so that we can compare.  Now there is a group of extremely minute, insect-like forms that are the parasites of birds.  Many of them are just plainly visible to the naked eye, others are too minute to be clearly seen, and others yet again wholly elude the unaided sight.  The epizoa generally lodge themselves in various parts of the plumage of birds; and almost every group of birds becomes the host of some specific or varietal form with distinct adaptations.  There is here seen a parasite that secretes itself in the inner feathers of the peacock, this is a form that attacks the jay, and here is one that secretes itself beneath the plumage of the partridge.

[Footnote 4:  A series of the eggs of butterflies were then shown, as were the objects successively referred to, but not here reproduced.]

Now these minute creatures also deposit eggs.  They are placed with wonderful instinct in the part of the plumage and the part of the feather which will most conserve their safety; and they are either glued or fixed by their shape or by their spine in the position in which they shall be hatched.  I show here a group of the eggs of these minute creatures.  I need not call your attention to their beauty; it is palpable.  But I am fain to show you that, subtle