35() REPORT OF STATE GEOLOGIST. 



quill, this provident mother prepares it for the reception of the eggs 

 by biting and roughening the bark with her jaws for a distance of 

 two or three inches. This bite is not gradual like that made when 

 feeding, but is sudden and vigorous, the insect chewing and pressing 

 the twig each side so as to form an edge. This operation is accom- 

 panied by a sudden nervous shake of the body from side to side, and 

 lasts sometimes but two or three minutes, sometimes more than ten. 

 When the operation is accomplished to her satisfaction, she clutches 

 with her front feet the stem to be used, and anchors the middle and 

 hindmost feet for the most part upon contiguous leaves or branches, 

 and often quite wide apart. Then, if she has her head in an upward 

 direction (for it seems to be immaterial to her whether the eggs are 

 placed from below up or vice versa), she begins at the lower end of 

 the roughened portion of the twig, and, after fretting it anew with 

 her jaws and measuring and feeling it over again and again with her 

 palpi, as if to assure herself that all is as it should be, she slowly — 

 with much apparent effort, and not without letting it partly fall 

 several times — curls the abdomen under until the lower edge of the 

 curved ovipositor is brought between the jaws and palpi, by which it 

 is grasped and guided to the right position. It is then worked slight- 

 ly up and down for from four to six minutes — all the time guided by 

 the jaws — while a shiny viscid fluid is given out apparently from the 

 ovipositor. Finally, after a few seconds rest or suspension of this 

 work, the egg gradually rises, and, as it passes between the oviposi- 

 tor, turns so that tlie one end appears almost simultaneously, from 

 between the convex edge, with the other from the lower tip. of the 

 blades. The egg adheres to the roughened bark in an oblique posi- 

 tion. It is at first almost black and highly varnished, but it acquires 

 its normal gray color within eight or ten hours. After the egg is 

 placed, the abdomen is straightened out and the insect rests for a 

 few moments, soon, however, to resume her efforts and repeat the 

 like performance, in every particular, except that the second egg is 

 placed on the opposite side of the twig and a little above the first 

 one. The third egg is puslu'd in between the top of the first one and 

 the twig, the fourth between the top of the second, and so on, one 

 on each side, alternately. Thus these eggs are not laid, as we might 

 naturally imply, one over the other, but rather, one under the other; 

 i. e., each succeeding pair having their ends thrust in between the 

 tops of the preceding pair, the teeth at the end of the ovipositor 

 helping to crowd the end into place. 



"The length of time required from the commencement of the 

 fretting of the twig to the proper placing of the egg varies all the 



