NUMBER OF EGGS. 1/5 



tions in the course of a year. The female white ant, whose 

 enormously distended body causes her to exceed her compa- 

 nions many hundred times in size, deposits sixty eggs in a 

 minute, which is at the rate of 211,449,600 in the course of 

 a year. Other insects are, however, less prolific. The silk- 

 Avorm produces only from 400 to 500 eggs, the caddice flies 

 less than 100; the burying beetles about thirty; and the 

 horsefly (Hippobosca equina) can only be said to deposit a 

 single egg. 



The eggs of insects are generally of an oval form (fig. 1, 

 oval-spotted egg of the fox-moth), the outer covering being 

 sufficiently rigid to resist ordinary external impressions ; 

 others are, however, soft and pliant. In some species they 

 are globose, as in many Lepidoptera (fig. 2, globular-banded 

 egg of the vapourer-moth) ; or conical, as in the large white 

 cabbage butterfly (fig. 3) ; cylindrical, pear-shaped, barrel- 

 shaped, &c. They are for the most part smooth ; but many 

 are very beautiful, ornamented with symmetrical ridges 

 (figs. 3 and 4, egg of the tortoise-shell butterfly), canals, 

 dots, &c., giving them, as Reaumur observed, the appearance 

 of embossed buttons. There are numerous other varieties 

 in the form of eggs, and some are furnished with appendages 

 for peculiar purposes. Thus the egg of the dung-fly (Scato- 

 pliaga putris, fig. 5) has two oblique props at one end to pre- 

 vent it sinking too deep in the matter upon which it is de- 

 posited ; whilst those of the water scorpion (Nepa cinerea, 

 fig. 10) are furnished with a coronet of spines, forming a re- 



