.INSECTA. 



pointed at the end, with a moveable appendage or species of finger under their 

 extremity, two eyes, each placed on a little immoveable pedicle. The body is 

 divided into two parts, the first of which, or the anterior, -is very small, and 

 bears the two first pair of legs, together with the eyes and mouth. 



Tromb. holosericeum, Fab. Very common in gardens in the spring; blood- 

 red ; abdomen nearly square, posteriorly narrowed, with an emargination ; the 

 back loaded with papillae, hairy at base, and globular at the extremity. 



There are various other subgenera, such as ERYTHR^EUS, GAMASUS, CHEY- 

 LETUS, OBIBATA, UROPODA, &c. 



Here we find our Common Ticks. The most remarkable is that of the 

 subgenus, 



IXODES, Latreille, Fabricius. 



The palpi forming a sheath to the sucker, and with it constituting a project- 

 ing and short rostrum, truncated and slightly dilated at the extremity. 



The Ixodes are found in thick woods abounding in brushes, briars, &c., 

 they hook themselves to low plants by the hind legs, keeping the others 

 extended, and fasten on Dogs, Oxen, Horses, and other Quadrupeds, and even 

 on the Tortoise, burying their suckers so completely in their flesh, that they 

 can only be detached by force, and by tearing out the portion that adheres to 

 it. These insects lay a prodigious quantity of eggs, and sometimes increase to 

 such an enormous extent on the Ox and Horse, that they perish from the 

 exhaustion. Their tarsi are terminated by two hooks inserted in a palette, or 

 united at the base on a common pedicle. 



The ancients designated these Arachnides by the term Ricinus. They are 

 our Ticks. 



CLASS III. 

 INSECTA. 



INSECTS, which form the third class of articulated animals provided 

 with articulated legs, have, besides, a dorsal vessel analogous to the 

 vestige of a heart, but totally destitute of any branch for the circu- 

 lation. They respire by means of two principal tracheae, extending, 

 parallel to each other, throughout the whole length of the body, hav- 

 ing centres, at intervals, from which proceed numerous branches, 

 corresponding to external openings or stigmata, which admit air. 

 They all have two antennae and a distinct head. The nervous sys- 

 tem of most Insects the Hexapoda is generally composed of a brain 

 formed of two opposing ganglions, united at base, giving off eight pairs 

 of nerves and two single ones, and of twelve ganglions, all inferior. By 



