INSECTS. 5 



aspect, and sometimes green. The circulation of 

 the blood is particularly conspicuous in Spiders, 

 and in some species of Cimex or Bug, in which 

 the vibrations and contractions of the arteries 

 may also be distinctly observed*. 



The first state in which Insects appear is that 

 of an ovum or egg. This relates to the generality 

 of Insects; for there are some few examples of vi- 

 viparous Insects, as in the genus Aphis, Musca,&c. 

 From the egg is hatched the insect in its second 

 or caterpillar state, [though the term Caterpillar 

 relates more particularly to the insects of one 

 peculiar tribe.) This second state has been gene- 

 rally known by the name of Eruca, but Linnaeus 

 has changed it to that of Larca, considering it as 

 a sort of masked form or disguise of the Insect in 

 its complete state. The Larvae or Caterpillars of 

 insects. differ very much from each other, accord- 

 ing to the different tribes to which they belong. 

 Those of the Butterfly and Moth tribe are gene- 

 rally and emphatically known by the name of 

 Caterpillars, and are universally known. Those 

 of the Beetle tribe, except such as inhabit the 

 waters, are of a thick, clumsy form, and the abdo- 

 men is commonly of a heavy or bulging appear- 

 ance. The Larvas of the Locust or Grasshopper 

 tribe, and of some others of the same order, do 

 not differ much in appearance from the complete 

 Insect, except in being destitute of wings. The 

 Larvae of Flies, Bees, and many others, are gene- 



* Especially in the Cimex lectularius or common bug. 



