— i6 — 



with a higher objective. Observe the sense papillae 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. 



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

 are as follows : — 



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

 maxilla. It is triangular in outline in this insect. 



Stipes. — The stipes or footstalk is the second .segment of 

 the maxilla ; it 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 termin- 

 ated by strong teeth ; this is the part known as the lacinia. 



Galea. — Joined to the distal end of the stipes, 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 slightly resem- 

 ble a dumb-bell in outline. The galea is known as the outer 

 lobe, upper lobe, or superior lobe. 



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

 between the cardo and the proximal segment of the galea is 

 a narrow sclerite ; this is the palpifer. 



Maxillary Palpus. — Articulated to the distal end of the 

 palpifer is a long, slender organ consisting of five segments ; 

 this is the maxillary palpus. 



After completing the drawing of the maxilla as a whole, 

 study the distal end of the distal segment of the maxillary 

 palpus with a higher objective, and make a drawing of this 

 part. 



