200 THE entomologist's record. 



lymph of the imago, nor can it be detected in the drab-coloured pigment 

 of the outer edges of the wings. The amount of uric acid in the fluids 

 of the alimentary tract of the pupa increases as the pupa becomes 

 older, so that the fluid which is voided upon emergence is always 

 strongly impregnated with it. In the case of Pieris rapae there is no 

 uric acid, either in the alimentary tract or haemolyraph of the larva, 

 but it is present in the alimentary tract of the pupa. It seems to me 

 probable that the uric acid of the alimentary canal of the pupa may 

 be a product of the metabolism of the hsemolymph that is removed 

 from the fluids of the body by the Malpighian tubules." 



It is important to notice that Mayer's proof that the scales are 

 formed from modified hypodermic cells makes them truly homologous 

 with the hairs of Arthropods. 



Another important fact insisted on by Mayer is that " the pupal 

 wings exhibit two sets of corrugations or foldings, one being parallel 

 to the trend of the nervures, and the other at right angles to it. In 

 either cross or longitudinal section these corrugations appear as a 

 regular series of ridges, and a single scale arises from the crest of 

 each ridge." 



He further writes : " Very large scales are found along the nervures 

 and upon the outer edges of the wings in A.arcJtippus. In fact, these 

 scales are so large, that, after the protoplasm has withdrawn from them, 

 a single leucocyte enters each one. These leucocytes soon degenerate, 

 and finally disintegrate, without, however, contributing directly to the 

 pigmentation of the scale. The fact that the leucocytes degenerate 

 after entering the scales indicates that the hsemolymph within the 

 scale is not in a normal condition." 



Another point insisted upon by Mr. Mayer is that " dull ochre- 

 yellows and drabs are, phylogenetically speaking, the oldest pigment 

 colours in the lepidoptera, for these are the colours that are assumed 

 by the hfemolymph upon mere exposure to the air Dull ochre- 

 yellows and drabs are at the present day the prevalent colours among 

 the less diflerentiated nocturnal moths. The diurnal lepidoptera have 

 almost a monopoly of the brilliant colorations, but even in these 

 diurnal forms one finds that dull yellow or drab colours are still quite 

 common upon those parts of their wings that are hidden from view." 



Since the above has been in type we have received from 

 Mr. Mayer another brochure, entitled, " On the colour and colour- 

 patterns of moths and butterflies." It is published by the Museum 

 of Comparative Zoology, Harvard College, Cambridge, Mass., U.S.A., 

 and is, in every respect, an essay which will still further enhance the 

 scientific reputation of the author. Our readers who are at all 

 interested in variation, mimicry, &c., must read the paper, or other- 

 wise they must remember they have missed one of the best and 

 most important of the papers yet published on these subjects. 



Some named Varieties in the Larentiids. 



By L. B. PKOUT, F.E.S. 



L;/ijri^ po/iulata ab. dotata (? Linn.), CI. — This is the form of L.pojni- 

 lata with the central fascia not darkened, hence only indicated by its 

 boundary lines. It is represented in many collections, and its occa- 



