284 THE entomologist's record. 



of the acUial cause of the patches, which was evidently what one 

 wished to arrive at. For every effect there was a cause, and the 

 question was, what causes certain portions of the wing of certain 

 Argynnids to develop these abnormal pale patches ? Mr. Frohawk's 

 statement that there was no pigment in the scales on these patches 

 made the matter a purely physiological one, for it showed that the 

 ordinary material — pigment-factor, as Dr. Riding termed it — had 

 never been deposited in the scales. What caused the failure of this 

 deposit '? is the next question. It could not be that at some pre- 

 vious stage the ancestral form had had no pigment in the scales in 

 certain portions of the wings, nor did Mr. South suggest this ; but, 

 in the cases which Mr. South relied upon — the pale patches in 

 var. valesina and other species— the scales forming these pale patches 

 were thoroughly pigmented, the mature pigment-factor only pro- 

 ducing a paler colour than the normal fulvous colour of the males of 

 such Fritillaries as A. papliia. Mr. Tutt considered that these pale 

 patches were analogous with similar pale patches in the Satyrids, 

 which also were often symmetrically, often very unsymmetrically, 

 placed on the wings. He referred to the recent researches of 

 Schiitter and others, that the scales in the course of development 

 went through the following stages: — (1) transparent, (2) white, 

 (;->) yellow (owing to the deposit of pigment-factor from the pupal 

 blood), (4) ordinary colour of matured pigment. It would appear, 

 then, that in these pale patches, either (1) the pigment-factor has not 

 been deposited, or (2) if deposited, had never get beyond stage 8, (yellow) 

 in its development. If these arguments were logical, then we had now 

 to consider what is the most likely explanation of this retarded scale- 

 development. Taking into account the known facts of the histolysis 

 of the pupal tissues, Mr. Tutt considered that anything that would 

 cause a local weakening of the tissue would produce a result similar to 

 that exhibited. This actual weakness of tissue might occur in the 

 larval period, when it would naturally be carried through the pupal 

 stage, or it might originate in the pupal stage ; whilst the possible 

 factors that might cause local weakness or disease in a larva or pupa 

 are manifold. He further pointed out that a well-known lepidopterist 

 had observed that when dust particles or other foreign matter inter- 

 fered with the pupa when it was in a very soft stage, i.e., during the 

 first hour or two following the change from the larval to the pupal 

 condition, the result always ended in crippling the imago or in the 

 failure of complete scale development in the neighbourhood of the 

 injury or irritation. Mr. Tutt supported Mr. South very strongly in 

 his suggestion that the time must now soon come when the butterflies 

 of this country will have to be placed in their proper genera, and 

 further agreed that we had at least three Argynnid genera among our 

 species, viz., (1) Dryas— paphia : (2) Brenthis — etiphrosi/7ie and 

 selene ; (3) Argynnis — adippe, aylaia (and, doubtfully, lathonia). — 

 Fcl)ruary 27th. — Mr. R. Adkin exhibited specimens of llyhnnia 

 li'Hcd/i/iacaria, Schiff., from Abbott's Wood. The pale and dark- 

 bordered were found in equal proportions, only one black specimen 

 was taken. Mr. Short : a bred series of Acroiiycta inyricae, with a 

 Dipterous, and a series of a Hymenopterous, parasite from its larva. 

 Mr. Billups recognised the latter as Iclinruwon fii-scipcs. Mr. Dennis : 

 two living females of W'spa r/cnnanira, taken in February. Mr. 



