No. 4.] METAMORPHOSIS OF THE FLAG WEEVIL. 185 



III. The Development of the Legs. 



Aside from a few not very recent accounts of the development 

 of the legs in Diptera, in which the leg buds are deeply invagi- 

 nated in the larva, Gonin's account of them in the butterfly 

 Pieris remains the only considerable one. And in Pieris there 

 are larval legs, well developed and functional from the first. It 



FIG. 4. Longitudinal section of the 

 middle leg in a grown larva, f, fat ; 

 /, leucocytes ; e, embryonic cells. 

 (Drawn from a preparation made in 

 my laboratory by Mr. C. Betten.) 



will be well, therefore, to 

 notice here some points in 

 the development of the legs 

 of this weevil. 



\Ye have already called 

 attention to Fig. 2, illustrat- 

 ing their origin. Fig. 4 is a 

 longitudinal section of the 

 leg of a grown larva, such as is shown in Fig. i . Three principal 

 divisions of the leg are already marked out by two deep con- 

 strictions. From the time of the beginning of the metamorphosis 

 the growth of the legs is extremely rapid. Fig. 5, A, represents 

 one of them as it appears after stripping off the larval skin just 

 before pupation. (Fig. 8 shows wing and leg together, and in 

 their relations to other parts.) The nine segments of the leg arc 



constitute the subject of another paper, which is now being prepared by a student 

 in mv laboratory. 



B 



FIG. 5. The leg of a larva, just before pupation. 

 A , the entire leg in outline, and in part in optic 

 section. B, a longitudinal section of the tar- 

 sus, f, femur ; t, tibia ; /, 2, 3, j, tarsal seg- 

 ments ; cl, claw ; s, developing tendon. 



