15 



glass. Examine it with a microscope using a low power and 

 reflected, not transmitted, light [i.e., turn the mirror so that 

 the field of the microscope is dark ; and place the micro- 

 scope so that a strong light falls upon the specimen). Make 

 a drawing of the caudal aspect of the labium, and letter the 

 parts. 



Study the distal end of the distal segment of a labial pal- 

 pus with a higher objective. Observe the sense papilhie with 

 which it is furnished. Make a drawing of this part. 



Parts of the maxillae. — After the removal of the labium 

 it is easy to distinguish the maxillae, of which there is one on 

 each side between the labium and the mandibles. 



Remove a maxilla and mount it in Canada balsam or 

 glycerine, with the caudal aspect uppermost. Examine with 

 a microscope using a low objective, and reflected light. 



Make a drawing of a maxilla, and name the parts, which 

 are as follows : — 



Cardo. — The cardo or hinge is the proximal part of the 

 maxilla. It consists of two sclerites ; the first is the larger 

 and is triangular in outline. 



Stipes. — The stipes or footstalk is the large, quadrangular 

 sclerite which forms the central part of the maxilla. 



Lacinia. — Articulated to the distal end of the stipes is a 

 large sclerite, which tapers distad, is curved, and is termi- 

 nated by strong teeth ; this is known as the lacinia j it is 

 called also the inner lobe. 



Galea. — Joined to the side of the stipes near its distal end 

 and projecting laterad of the lacinia is a part consisting of 

 two segments. This is the galea. The distal segment of the 

 galea is large, spoon-shaped, and covers the inner lobe like a 

 hood ; the proximal segment is constricted in the middle so 

 as to'resemble slightly a dumb-bell in outline. • The galea is 

 also known as the outer lobe, tipper lobe, or superior lobe. 



Palpifer. — Joined to the lateral border of the stipes and 



