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and imago (eventually also pupa) of other forms than the Sphingids, [ feel 
convinced, that it may be proved for a great many Lepidoptera, e.g. 
Saturnidae and many Bombycidae, and certainly also for Geometridae. 
From the above mentioned observations I feel justified in making 
the following deductions : 
The markings on the body of caterpillars, pupae and imagines 
follow the same rule as those on the wings of the latter. Conse- 
quently the original design is regular, simple, limited to each segment 
separately, complete, uniform over the whole extent of the segment, 
bound to the dispersal of the setae over its surface, and to the 
division of the latter into secondary rings or annuli. The colour, 
in which this pattern is executed, may differ, and is of no account 
as to its real character. Yet there exists a certain connection 
between different hues: green for instance always appearing as a 
secondary modification of other shades, especially brown, grey or yellow. 
Modifications of the original pattern take place in a similar way 
and after the same rules as those on the wings. Through the accen- 
tuation of a contrast in shades between neighbouring spots, which 
originally were similarly coloured, a richer gamma of hues may be 
produced. Vertical, horizontal and oblique lines are formed by coa- 
lescence of rows of primary spots; maculae, eye-spots, bands and 
areas result from the accrescence of spots and (or) their blending with 
others in their vicinity. Finally the whole bulk of the separate 
spots may merge into one general shade. 
Attention should also be paid to the fact, that in the same way 
as the front-seam of both wings is often marked in a different and 
stronger way than the rest of the surface (especially at the under- 
side), the first annulus of each segment likewise surpasses the rest 
of the annuli in sharpness of design and coloration. 
However restricted the material for my investigations may have 
been, it has convinced me still more of the validity of my 
assumption, that a primary relation exists between the colour-design 
of caterpillar, pupa and imago, the pattern of the imaginal instar often 
showing a more primitive type than that of the fullgrown caterpillar. 
The contrast between thoracal and abdominal pattern, which 
already in the younger instars of the caterpillar manifests itself in 
the different distribution of the setae (comp. J. T. Oupemans and A. 
SCHIERBEEK), maintains itself as well in the later instars by differen- 
ces in colour and design, occurring in the great majority of cater- 
pillars. An identical design on thorax and abdomen. is probably the 
result of secondary change. 
Groningen, January 1920. 
