176 THE CAUSES WHICH PROPAGATE 



sun to shade, we find the individuals decrease the fulness of their 

 notes, but prolong their length and number, the strokes of the 

 hind legs attaining to twelve or fourteen in the dusk and the 

 stridor lasting from four to five seconds. So at morning the 

 male commences a single prolonged note, which only relapses 

 into the ordinary music when the sun appears and he has reposed 

 a little in its beams. At midsummer, in the Alps, the snatches 

 barely exceed a second, while during September they become 

 lengthened out to two. Generally we notice from seven to 

 eight notes, '"'' Reee ! " or " Rreee ! '' which increase in intensity ; 

 these last for about two seconds, with intervals of about three. 

 The male still continues its recitative until late in October over 

 heaths and on woodland greensward, where the sunbeams pene- 

 trate ; and here I have myself come upon him meting out a slow 

 series of four sounding and emphatic strokes, " Thiph ! thiph ! 

 thiph ! thiph ! " curtained by the deep umbrage and silent 

 gloom cast by afternoon shadow. Sundown even does not 

 invariably quench his chronic loquacity from out the damp 

 fungi and mouldering vegetation. The musical tubercles on the 

 hind legs of this wiry grasshopper I have portrayed, after Dr. 

 Landois, on Plate II., Fig. 7. In those examples I have myself 

 examined they were invariably less pointed, and in places were 

 apt to be wanting, irregular, or laterally supplemented. They 

 are rather wide apart as to insertion, and vary as to number 

 even in the same species ; Dr. Landois having enumerated in 

 one male ninety-three on the left femur and only eighty-five on 

 the right. The stridor is thought to arise from their impinging 

 on the elytral vein only when the hind legs are thrust downwards. 

 Stenobothrus lineatus, Panz., another species not uncommon 

 in fields among rank grass, is at first sight liable to be confounded 

 with this grasshopper ; but after a while one may learn to dis- 

 tinguish it by its delicate wing-covers and brighter hue, as also 

 by a white streak along the front margin of the abbreviated 

 wing-cases of the sluggish female — a characteristic that has 

 given rise to its trivial name. Both kinds are found in this 

 country, and have very similar distribution over the j)lains and 

 mountains of Europe; though if any one on meeting with 

 lineatus in an idle hour should care to lounge on the grass and 

 observe its laconic ways, he would at once be struck with its 



