DEAD-LEAF-LIKE BUTTERFLIES 205 



with that which is common in other Nymphaline butter- 

 flies {Kalliina, DolcscJiallia, Anaea, Precis , &c.), viz. the 

 resemblance not to a fragment but an entire dead leaf, 

 with midrib and suggestion of lateral oblique venation. 



Holes may not only be suggested by opaque ' body- 

 colour ' and by transparent windows, but also by actual 

 discontinuity, as is probably the case in certain species 

 of Anaea in which the deeply-cut bay in the inner margin 

 of the fore-wing may be converted into the likeness of 

 a hole by closure along its open side by the costal margin 

 of the hind-wing. The holes represented in these apparent 

 entire dead leaves seem to have been produced by gnaw- 

 ing* ^-g"' ^^ insect larvae.^ They are surrounded very 

 conspicuously with a marginal zone of modified colour 

 varying greatly in different individuals as regards both 

 tint and breadth. This border of altered colour may 

 represent the effect of the attacks of fungi entering along 

 the freshly exposed tissues of the edge. On the other 

 hand, in the leaf-fragment suggested by C-alb7im the forces 

 of the inorganic environment, which by their prolonged 

 action have produced the wear and tear of the margin, 

 have also been responsible for the more centrally-placed 

 discontinuity. Comparing various species of the genus 

 Polygonia {Grapta), it is seen that the curved C-Hke 

 window occurs in several ; in some the suggested rent is 

 V-like, while occasionally the mark appears to represent 

 a hole of a reniform shape.^ 



Another interesting point in the likeness to a dead leaf 

 is the appearance of fungus-growth, finely described b)- 



^ Mr. W. B. Grove, of Handsworth, Birmingham, who was present at 

 the Huxley Lecture, afterwards sent me leaves of several plants attacked 

 by minute fungi, species of Phyllosficia and Cercospora. The attack was 

 local and followed by the death and disappearance of the central portion 

 of the leaf-tissue of each patch, leaving a roundish or oval window out- 

 lined with brown, sometimes in the form of a narrow line, sometimes 

 spreading centrifugally into the leaf for a greater or less distance. I have 

 no doubt that Mr. Grove is right in believing that the ' windows ' of 

 Kalhma resemble perforations made in this way, and not, as I supposed, 

 by the gnawing of larvae followed by fungus attack along the raw edge 

 of the aperture. See Proc. Eni, Soc, Lofid., June 7, 1905. 



^ See Idt'd. May 6, 1903, for the account from which the foregoing 

 description has been adapted. 



