PARTS OF INSECTS, AND MISCELLANEOUS OBJECTS. 123 



EGGS. The eggs of birds, though differing in color, possess nearly the same 

 form, varying only by slight changes between an oval and a globular shape. Such 

 however is not the case with those of insects, which exhibit an endless variety 

 of exquisite forms often most beautifully and elaborately wrought, and bearing a 

 resemblance to richly carved work. " We meet with them," says Kirby, " of the 

 shape of the common hen's egg, flat, round, elliptical, conical, cylindrical, hemi- 

 spherical, pyramidal, square, lens-shaped, turban -shaped, pear-shaped, boot-shaped, 

 and sometimes of shapes so strange and peculiar, that we can scarcely credit their 

 claim to the name of eggs." Indeed, the empty shells left upon the leaves of 

 plants have been mistaken for minute flower cups, and according to Reaumur 

 were once actually thus delineated by a naturalist, who was extremely perplexed 

 to account for the origin of these singular blossoms. Among the most rich and 

 elegant forms, are those which belong to the eggs of butterflies, the surface being 

 often exquisitely sculptured and profusely adorned with ornaments. Four varie- 

 ties are delineated in drawings 202 axxi 203 as they appear when highly magnified. 



Fig 202. Fig. 203. 



In this group, a 202, is the egg of a butterfly called the Hipparchia Tithonus ; it 

 is of a dome-shaped form, strengthened and adorned with longitudinal ribs, sym- 

 metrically arranged and connected by cross lines; c 203, is the egg of another 

 kind, the Hipparchia Furtina, and is crowned at the top with circular rows of 

 scales, overlapping each other likes the plates of armor or the scales of fishes. 

 The same type is observed in the egg of the Noctua Nupta, at figure b 202, 

 where the end of the egg is presented to view; and towards which numerous 

 strongly defined ridges converge. Between these ridges the surface is deeply 

 fluted. The eggs of many insects are provided with a small lid or cover, which 

 when the young insect within has arrived at maturity it throws off at its will, 

 and emerging, through the opening thus made, from the enclosing shell, enters at 

 once upon its new state of existence. In addition to this provision, a curious 

 contrivance is found in the egg of a certain species of bug, and which is shown 

 at d 203. It consists of a horny substance in the shape of a cross-bow, the 

 bow being attached to the lid, and the handle to the upper end of the side of 

 the egg. It is supposed to be designed to facilitate the egress of the young when 

 it is ready to leave the shell. 



HAIRS. The hairs of different animals afford beautiful objects for microscop- 

 ical examination. Those of the common mouse which are shown in drawings 204 



