THE HOUSE-CRICKET 



189 



found in the cricket also, but with remarkable modifica- 

 tions. The outlet of the salivary duct now becomes 

 double and capable of protrusion. When protruded, it 

 spreads out fan- wise, and each half forms a quadrant, upon 

 which the stiffening fibres ramify. When not in use, the 

 whole is retracted. The two expansions when protruded 

 form a semicircular plate, convex towards the mouth, and 

 well adapted for spreading the salivary fluid upon the 

 food. Since the house-cricket is notoriously thirsty, it 



FIG. 40. Protruded tongue of house-cricket, highly magnified. 



may be that its expanded tongue finds a special use in the 

 lapping up of liquids spilt on the hearth. 



Beyond the capacious pear-shaped crop of a cockroach 

 comes the gizzard, a blunt cone with muscular walls, ap- 

 plied by its base to the broad end of the crop, and tapering 

 at the other end into a tube with folded walls, which passes 

 a long way into the stomach. It is easy to slit open this 

 gizzard, and clearing it with potash solution, to study the 

 arrangement of the strong chitinous ridges which project 

 inwards from all sides. The cricket has a similar gizzard, 

 which may be prepared for examination in the same way. 

 Here the ridges are broken up into a great many sharp 

 teeth, and seem to be adapted for tearing the food, while in 

 the cockroach one might suppose that they act rather as a 



