684 



EGGS OF INSECTS. 



of great beauty, on account of the regularity of their form, and the 

 symmetry of the markings on their surface (Fig. 352). The most 



Eggs of Insects, magnified : — a, Pontia napi; b, Vanessaurticce ; 

 c, Hipparchia tithous; x>, Argynnis Lathonia. 



interesting belong for the most part to the Order Lepidoptera ; 

 and there are few among these that are not worth examination, 

 some of the commonest (such as those of the Cabbage-Butterfly, 

 which are found covering large patches of the leaves of that plant) 

 being as remarkable as any. Those of the Puss-moth (Cerura 

 vinula), the Privet Hawk-moth (Sphinx ligustri), the small 

 Tortoise-shell Butterfly ( Vanessa urticce), the Meadow-brown 

 Butterfly (Hipparchia janira), the Brimstone-moth (Rumia cratce- 

 gata), and the Silk-worm (Bombyx mori), may be particularly 

 specified ; and from other orders, those of the Cockroach (Blatta 

 orientalis), Field Cricket (Acheta campestris), Water-Scorpion 

 (Nepa ranatra), Bug (Cimex lectularius), Cow-dung-fly (Scatophaga 

 stercoraria), and Blow-fly (Musca vomitoria). In order to preserve 

 these Eggs, they should be mounted in fluid in a cell ; since they 

 will otherwise dry up and may lose their shape. — They are very 

 good objects for the ' conversion of relief effected by Nachet's 

 Stereo-Pseudoscopic Microscope (§ 29). 



533. The remarkable mode of Reproduction that exists among 

 the Aphides must not pass unnoticed here, from its curious 

 connection with the Non-Sexual reproduction of Entomostraca 

 (§ 502) and Rolifera (§ 361), as also of Hydra (§ 411) and 

 Zoophytes generally, all of which fall specially, most of them 

 exclusively, under the observation of the Microscopist. The 

 Aphides which may be seen in the spring and early summer, and 

 which are commonly but not always wingless, are all of one Sex, 

 and give birth to a brood of similar Aphides, which come into the 

 world alive, and before long go through a like process of multipli- 

 cation. As many as from seven to ten successive broods may thus 

 be produced in the course of a single season ; so that from a single 

 Aphis, it has been calculated that no fewer than ten thousand 

 million millions may be evolved within that period. In the latter 



