JANUARY. 13 



wouud and instil a poison ; it is used both as an offensive 

 and defensive weapon. The ovipositor is the instrument 

 which serves to pierce wood or the bodies of animals^ in 

 order to deposit eggs. 



The legs in insects are divided into the coxa, or hip, of 

 two joints ; i\\.Q femur, or thigh ; the tibia, or leg ; and the 

 tarsus, or toe. The number of joints in the tarsus is in 

 some orders constantly five, but in others it varies from 

 one to five, and sometimes the posterior or hinder tarsi 

 have a joint less than the anterior. Upon the differences 

 in these numbers are established the chief divisions in the 

 order Coleoptera. The last joint of the tarsi is almost 

 always terminated by two hooks. 



In the form of the feet, and more particularly of the 

 tarsi, there are many varieties, according to the habits of the 

 insects. The anterior pair have sometimes \kvQ femur or thigh 

 grooved and armed with dentations, and the tarsi terminated 

 by a strong spine : insects having the anterior feet con- 

 structed in this manner, use them for seizing their prey, 

 and are termed Raptorii. Others have the tarsi flat and 

 hairy, this form enabling the insect to employ them as oars, 

 or for swimming ; these are called Nataiorii. In the Bee 

 family the legs are formed in such a manner as to brush off 



