1141 
Zoology. — “The colourpattern on Diptera wings.” By Prof. J. F. 
VAN BEMMELEN. 
(Communicated in the meeting of March 31, 1917). 
\ 
The investigation of the colour patterns on the wings of Lepidoptera 
brought me to the convietion, that in their markings original and 
modified motives of design could be distinguished, the first being 
arranged in strict dependency on the nervural system and in regular 
repetition over the whole of the wing-surface. This result fore- 
shadowed the probability, that on the wings of other orders of 
insects similar arrangements of pattern might be met with, which 
would allow of a similar distinction between a primordial pattern 
and its later or secondary modifications: the primitive pattern in 
the same way being directed by the course of the veins in its 
distribution over the wing-surface. And as the comparative investi- 
gation of the nervural systems in different orders of inseets had led 
to the final conclusion that all of them represent modifications of 
one common groundplan, the supposition that a similar fundamental 
connection might exist between the primitive colour-markings, occur- 
ring between those nervures, became extremely probable’). 
Starting from this supposition, J. Borkr’) argued, that the similarity 
between the colour-pattern on the wings of Cossids, Micropterygids, 
Hepialids and other Lepidopterous families, and those of Trichoptera 
and Panorpata, should not be considered as a merely accidental 
resemblance, but depended on a real homology. Evidently it is 
worth while to extend this investigation to the remaining Insect-orders. 
That I take the Diptera as a starting point, is in no way due to 
the opinion, that a near relationship exists between this order and 
Lepidoptera, nor is it because I should consider the Diptera as 
especially primitive insects; it is in consequence of a recent (1916) 
publication by J. H. pr Meters: Zur Zeichnung des Insekten-, im 
besonderen des Dipteren- und Lepidopteren-fliigels, in which he has 
treated these two orders in succession, and noted equivalent features in 
them, though he has carefully abstained from drawing comparisons 
between them in details. 
Now pe MeijerE does not acknowledge my distinction between 
primary and secondary wing-markings, nor does he accept the 
1) Vide NeepHam and Comstock, The wings of Insects, American Naturalist, 1898. 
2) J. Borre, Les motifs primitifs des ailes des Papillons et leur signification 
phylogénétique. Onderzoekingen verricht in het Zoöl, Lab, der Rijks-Universiteit 
Groningen V, 19.6, Tijdschr. d. Ned. Dierk. Ver. 2de Ser. Dl. XV. 
13% 
