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W. L. TOWER. 



thin layer of exuvial fluid is found, especially in the anterior parts 

 of the body between the hypodermis and cuticula, and the inner 

 surface of the cuticula appears rough and corroded. This corro- 

 sion of the inner side of the secondary cuticula continues until it 

 is often almost entirely removed, as shown in Fig. 5. 



FIG. 5. C. femorata. Section of the integument from same location as the sec- 

 tion from which Fig. 4 was taken, showing decrease in thickness of the secondary 

 cuticula and great extension of the basal ends of the hypoder.iial cells to form a rela- 

 tively thick but open layer of hypodermis. 



This dissolving of the secondary cuticula is a most constant 

 phenomenon in ecdysis and has been foundin all the insects that 

 I have examined, but in varying degrees. The same disintegra- 

 tion of this layer is shown in Fig. 6 of L. decimlineata. 



This origin of part of the exuvial fluid in L. decimlineata and 

 of all of it in C. femorata has not, I believe, been heretofore 

 suspected but we can at once see the great utility of this process 

 and especially the advantage gained in having the cuticula thinned 



