294 SUMMARY OF CURRENT RESEARCHES RELATING TO 



the discnssion of the synthetic power of the higher animals, the possible 

 action of the micro-organisms in the intestine must also be considered. 



Patterns of Wings in Lepidoptera.* — J. Botke has made an 

 elaborate comparative study. The primitive design of wing-pattern in 

 Lepidoptera is not that of transverse bands (as Elmer believed), nor of 

 spots as in Zeuzera, but of transverse inter-nervural tracts. The 

 Cossidse may be regarded as somewhat primitive. In the genus 

 Eriocrania there is at once primitiveness and originality ; in E. spar- 

 manella the design consists solely of tracts. 



In Trichoptera the motifs and main modifications of these are the 

 same as in Lepidoptera. The relation between primary and modified 

 motifs is the same in the two orders. The primitive design in Trichoptera 

 is probably the same as in Lepidoptera. 



From the primitive motif may be derived the reticulate scheme, the 

 inter-nervural rows of spots in Zeuzera, the arched tracts of Hepialid^e 

 and some other families, and other patterns duly detailed. From the 

 reticulate scheme can be derived the longitudinal figures, denticulate or 

 with approximately straight contours {Cossus pahnaris and Endoxyla 

 ligneus), the transverse bands, and the spots. The "eyes" of Stnerinthus 

 ocellata are derived from transverse bands. 



The primitive Lepidoptera were not white, but had a design 

 borrowed from lower types, such as primitive Panorpidge. The 

 coloration of nervures is perhaps in part an independent motif and in 

 part the result of an extension or a disappearance of the ornamentation 

 of the " cells." The pigment was primitively carried by the membrane 

 of the wing, afterwards in the scales, the membrane losing it. 



Setal Pattern of Caterpillars and Pupge.t— A. Schierbeek Ira* 

 made a detailed comparative study of the disposition of the setaj in 

 caterpillars and pup?e. He comes to the following conclusions : The 

 organization of the thorax is secondary. The anal segments vary in 

 number in different species. All the abdominal segments had originally 

 a pair of legs. Various types of arrangement can be defined and form 

 a series, one type leading on to another. A metamerically repeated 

 pattern of pigment spots is more primitive than a pattern of stripes. 

 The change of setfe into verrucae is a reversible process. 



From the agreement of the pupal pattern with that of the first instar 

 and its difference from that of the last larval instar, the hypothesis has- 

 been developed that the pupa and the first caterpillar instar are both 

 primitive states. The other larval instars are to be considered as 

 secondary adaptations. The pupa is to be considered as a subimaginal 

 stage which secondarily has become non-mobile. The caterpillars of 

 the° various families have for the greater part developed independently 

 of or parallel to one another. A general larval pattern for holometabolic 

 insects has not been established with any certainty. 



* 



Onderzoekingen Zool. Lab. Rijksuniversiteit Groningen, No. v. (1916) pp. 



1-147 (4 pis.). 



t Onderzoekingen Zool. Lab. Rijksuniversiteit Groningen, No. vi. (1916) pp. 



1-156 (5 pis.). 



