610 ROBERT MATHESON 



undergoing division scattered throughout the muscles. However, 

 the number that divide is very small. 



Figure 24 shows a more advanced stage in muscle regeneration. 

 The longitudinal muscles show not only the cut ends of fibrillae 

 but have assumed their definitive arrangement, side by side 

 immediately beneath the epithelium. The fibrillae show dis- 

 tinctly in the circular muscles. Figure 25 shows a somewhat 

 older condition while figure 26 shows the beginnings of the cross 

 striations in the muscle fibers. In a pupa ten days old the muscles 

 have assumed their definitive form, though the cross striations 

 do not show as clearly as they will become in the adult. 



The type of histogenesis of the intestinal muscles in Corydalis 

 is that described under (2) . We have first a chemical liquefying 

 of the muscles in place, beginning around the nuclei as centers. 

 The leucocytes, which surround and penetrate between the muscle 

 layers, undoubtedly take up and digest some of the broken down 

 tissues. After the chemical liquefaction the larval nuclei, though 

 some of them degenerate, become rejuvenated, and from them and 

 the surrounding cytoplasm are built up the imaginal muscles. 



CONCLUSIONS 



1. The fore-gut of the larva of Corydalis may be divided into 

 five well marked regions: pharynx, oesophagus, gizzard, portion 

 between gizzard and oesophageal valve, and oesophageal valve. 



2. The pharynx is provided with a series of dilator muscles 

 attached to the walls of the head. The oesophagus presents no 

 features of peculiar interest except perhaps the large number of 

 longitudinal folds which permit a very great distension of its 

 lumen. 



3. The gizzard is well developed. Although Plateau ('74) and 

 a number of workers following him have assigned to the gizzard 

 only a straining function, it is evident that in Corydalis it exer- 

 cises a grinding and crushing action as well. This is evidenced 

 by the development and arrangement of muscles, the powerful 

 chitinous teeth and their method of interlocking. Bordas ('05) 



