STRUCTURES IMPLICATED IN METAMORPHOSIS. 15 
large back plate and the margin of the body, in the engraving. 
The large cross piece and the smaller side plates form the dorsal 
arch. In the centre of the lower side of the segment two 
LARVA OF Calosoma sycophanta. 
Magnified upper and under sides (dorsal and ventral). 
transverse series of solid plates may be noticed, the first formed 
of a single large piece, the second of a range of four very 
small ones. By their coalescence these separate portions will 
eventually form the ventral or sternal lamina or plate. The 
simple arch of the segments of the abdomen of lepidopterous 
