414 



MERISTIC VARIATION. 



[part I. 



* 



As is usual with appendages the whole length of the antenna? 

 differed a good deal independently of the number of joints. 

 621. On comparing antennas with different numbers it seemed that 

 the proportional length of the first two joints was nearly the 

 same in all, but in the third joint there was great difference, as 

 shewn in Fig. 124. The left antenna in Fig. 124, I may be 

 taken to be the normal form with 14 joints. In it both 3rd and 

 4th joints are small. The right antenna of the same specimen 

 has 13 joints and in most of the 13-jointed antenna? the arrange- 



Fig. 124. Various forms of antennas of adult Earwigs {Forficula auricularia), 

 all from one garden and taken at one time. 



I. Specimen having the left antenna normally 14-jointed, and the right 

 13-jointed. No. 621. 



II. Both antennae 13-jointed. No. 622. 



III. Both antennae 12-jointed. No. 623. 



IV. Bight antenna normally 14-jointed ; left antenna 12-jointed. No. 624. 



Note that the rights and lefts are arranged as marked by letters r and I. The 

 antennae were so fixed for drawing in order to bring them side by side after the 

 bend from the first joint. This figure was drawn with the camera lucida by 

 Mr Edwin Wilson. 



ment was much as shewn in this figure. As shewn, the 3rd joint 

 especially is here rather longer than in the 14-jointed form, but 

 several of the peripheral joints are also a little longer, so that 



