297 



bered, else it might appear that the earher instars are larger 

 than the later. In some of the cases the specimens have been 

 reversed, so that a left leg is on the right side, or vice versa. 



The leg operated on was generally the left of the third pair ; 

 these give no pupal record. When a leg of the first or second 

 pair is treated, its condition leaves a record in the pupa. 



The photographs of the larval legs are from the cast skins 

 mounted in Canada balsam. In some cases a skin got lost, in 

 others it was broken or injured, and in some it proved difficult 

 to unravel from a shrivelled-up cast skin, and had to be mounted 

 in an unsatisfactory way, in case it should be broken b}- further 

 manipulation. Some of the illustrative specimens selected for 

 photographing have some of these defects, but are such as show 

 what is desired, and as are characteristic of the group of specimens 

 to which they belong. 



Last Larval Instar : Tarsal Joint removed. — In fourteen 

 specimens, in eight of which the tarsal joint was partially and 

 in six wholly removed, the tarsus of the imago was normal. 



In nine other specimens the tarsal joint was completely 

 removed in five, and in four others the cicatricial tissue 

 appeared to infringe on the tibial joint. How far this is so 

 is necessarily more or less doubtful in this and other groups. 



In the first five there is complete regeneration in one case. 

 In two others the new tarsus is of reduced size, but otherwise 

 normal. In one there are only three tarsal joints of approxi- 

 mately normal size. The fifth of these has three tarsal joints, 

 of a length equal to two normal (proximal) joints, but a rounded 

 nodule represents the last two joints. This specimen is re- 

 markable as having no claws, which are almost in\ariably 

 present, no matter how reduced the other elements of the Hmb 

 are. 



In the four specimens with certainly the whole tarsus, 

 possibly some of the tibia removed, one has a tarsus normal, 

 except that it is only 3 mm. long instead of a normal 43 mm. ; 

 one has a single-jointed tarsus (fig. 6) ; two have a single- 

 jointed tarsus, but with the claws at some distance from the 

 extremity (fig. 8). 



Last Larval Lnstar : inorc or less of Tibia removed. — Of these 

 there are twenty-three specimens. One of these wants the 

 38 



