Tin: STBUl TUBS OF TN8E0TB 7 



edge, adapted for biting. The mandibl< I on 



each side of the mouth-opening. Behind the mand 

 are the maxillae i Pig. ! (, which are divided into t h r< 

 the inner armed with teeth or spines, the middle lobe un- 

 armed and Bpatula-shaped, while the outer forma a five- 

 jointed feeler called the maxillary palpus. The maxillae are 

 accessory jaws, and probably serve to hold and arrange the 

 food to be ground by the true jaws. The floor of the mouth 

 is formed by the labium (Figs. 1 and \! ). which in reality 

 is composed of the two second maxillae, soldered together in 

 the middle, the two halves being drawn separately in Fig. 1. 



Within tlic mouth, and situated upon the labium, is the 

 tongue (lingua), which is a large, membranous, partly hol- 

 low expansion of the base of the labrura; it is Bomewhat 

 pyriform, slightly keeled above, and covered with fine. >titT 

 hairs, which, when magnified, are seen t<> be lot »ugh, 



chitinous spines, with one or two slight points or tubei 

 on the side. These stiff hairs probablj serve to retain the 

 food in the mouth, and are, apparently, of the - truc- 



ture as the teeth in the crop. The b te is 



narrow, and extends back to near the pharyn n trance 



to the gullet), there being on the floor of the mouth, behind 

 the tongue, two oblique slight ridges, covered with >titT. 

 golden hairs, like those on the tongu . 



The student may separate the body, after being hardened 

 in alcohol, into the parts represented by Fig. 1. as indicated 

 h. the table on the following page, and neatl) gum them in 

 their propei- order upon a card with liquid glue or mucil 



Internal Anatomy. The internal anatomy may be stud 

 by removing the dorsal wall of the body, and also by harden- 

 ing the insect several days in alcohol and cutl in two 

 longitudinally by a sharp scalpel. 



The oesophagus (Fig. 4. a) is short and contin- 



uous with the roof of the mouth. There an 

 tudinal irregular folds on the inner surfa- ■ It termit I a 

 in the centreof the head, directly under tin r supra- 



OBSophageal ganglion, the end being indicated by several 



