WOOD-CORING BEETLES 15 



terrifies nervous old ladies by its ticking, its relative A. 

 paniceum attacks the stores of comestibles, works of 

 art, and literature of the dwelling, and between them 

 they would, in the course of time, if unchecked, produce 

 terrible ruin. 



When found in woodwork out of doors, the direct 

 damage insects of this kind do by the actual excavation 

 and devouring of the wood is not the only injury for 

 which they are responsible; for damp air enters the 

 substance of the wood through the burrows, and meet- 

 ing with the excrement, which is stored in great quan- 

 tities in the burrows, renders it a good basis for the 

 growth of microscopic fungi, whereby the decay of the 

 wood is accelerated. 



All the insects hitherto enumerated belong to the 

 family Ptinidce, of which they constitute one section, the 

 Anobiides, distinguished, at least so far as our house- 

 feeders are concerned, by their more cylindrical form, 

 compact make, and shorter legs. In the other section, 

 the Ptinides, to which we now turn our attention, the 

 shape is more globose, the antennae and legs much 

 longer, and the thighs so much thickened at the outer 

 extremities as to become club-like. From their shape 

 it would be easy to conjecture what would be in accord- 

 ance with facts, that they have less to do with cylin 

 drical burrows than their companions who "swear by" 

 Anobium. 



The typical genus of the Ptinides is Ptinus, and the 

 commonest species of that genus P. far (Fig. 5). This is 

 also a household insect, and is of somewhat varied habits. 

 It well exemplifies a peculiarity exhibited with more or 

 less distinctness in several species of this genus, viz., dis- 

 similarity in shape between the sexes : the body of the 

 male is almost cylindrical, but that of the female inflated 



