CHAP. III. | METAMORPHOSIS. 20 



aiea is usually considered as the apex of the egg, the opposite side 

 being the base, and the intervening portions being called the walls 

 or sides. It follows from this that, in the case of an egg attached 



to a surface, the attached portion is not necessarily the base. As 

 regards shape, eggs are rarely perfectly spherical but are usually 

 more or less flattened or produced in one or more directions. The 

 outer surface of the shell is sometimes most elaborately sculptured 

 or ornamented, sometimes merely covered with rough pittings or 

 elevations which may be arranged in roughly polygonal reticula- 

 tions, or may be quite smooth- The method of deposition is equal!) 

 variable; in some groups the eggs are laid singly, either scattered 

 at random or carefully deposited in, on or near suitable food for 

 the future hatchlings, in other groups the eggs ma\ be laid in a 

 mass sometimes covered with clown from the body of the parent or 

 with waterproof varnish or enclosed in a common shell or covering 

 which may exhibit most elaborate structure. Amongst the most 

 familiar ot types of egg-masses found in India are those of various 

 Mantids which are so commonly seen attached to twigs, walls, etc. 

 The number of eggs deposited varies very greatly in different 

 insects from a dozen or less (some wasps, probably Hippoboscids) 

 to several hundred or, in some social insects (Honey Bees, Term- 

 ites), many thousands perhaps over a million. The embryological 

 development of Insects cannot be discussed here and it must suffice 

 to say that the hatchling insect, when it has attained its full 

 embryonic growth, escapes from the egg, often by gnawing a 

 passage through the shell with its mandibles in the case of eggs 

 deposited singly, but some larvae have special organs for opening 

 the shell and others merely rupture it by their contortions. 



The term " larva," though often applied to all insects in an 

 active ante-imaginal condition, is better restricted to denote the 

 second stage of those insects which possess a true pupa, the word 

 " nymph " being used for the immature, active stages of those 

 insects in which metamorphosis is slight (grasshoppers, bugs, etc). 

 In popular language, in the case of butterflies and moths the larva 

 is often called a " caterpillar," in Hies a " maggot," and in beetles 

 and wasps, etc., a "grub." but the term "larva " is more properly 

 Used to denote a stage which is strictly homologous in all these 

 four Orders. 



emi "embryonic" is hen individual in the inactive 



egg-stale only but the embryonic condition i< oiupleted until the insert has 



assumed adull characters, Vnte-nat 



some of the lower moths (I'yralidte, Tortricina and i which the egg-shell is 



• >ftcn so transparent .i^ to facilitate 



