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THE BOOK OF NATURE STUDY 



which is not a true appendage (modified limb), attached to the 

 lower border of the front of the head (clypeus). Behind this is a 

 pair of strong mandibles, bearing three horny teeth near their tips, 

 and roughened grinding surfaces near the base. With these the 

 cockroach is able to feed upon almost anything that contains 

 nourishment; leather, paper, hard crusts, the dead bodies of 

 their fellows, and even the human skin is attacked by them. 

 It is said that they devour bed-bugs ; and on board ship they 

 are sometimes a serious nuisance, owing to their attacks upon the 



FIG. 64. Mouth appendages of cockroach. A, labium : a, labial palp ; b, line 

 of attachment to head. B, first maxilla : a, galea ; <, lacinia ; <r, palp ; 

 d, stipes ; <?, cardo. C, mandible. 



skin of sleeping persons. The mandibles, and also the first pair 

 of maxillae which immediately succeed them, meet their respective 

 fellows in the middle line, striking inwards from right and left. 

 The first maxillae consist of a short horizontal " cardo " near 

 to the head, a longer, vertical " stipes " from the outer side of 

 whose distal extremity arises a 5-jointed palp. Beyond the 

 origin of this tactile and probably gustatory organ there are 

 articulated to the stipes two pieces, an outer " galea " and an 

 inner " lacinia.'* The galea is deeply grooved along its inner 

 face in order to afford a sheath in which the lacinia may lie, much 

 as the blade of a pocket knife lies in the handle ; at its extremity 



