84 THE entomologist's record. 



considers the facts erroneous, but if so they should be so proved ; 

 perhaps he thinics the arguments unsound, then he should disprove 

 them ; at any rate the subject which Mr. Mansbridge suggests has 

 not received attention is discussed at length and supporte i by facts 

 which Mr. Mansbridge possibly could controvert. Yet we wonder 

 whether ]\Ir. Mansbridge has ever read or studied the details. 



This, however, may have been an oversight of Mr. Mansbridge's, 

 but has he also overlooked the paper on " Pupal development and 

 Colour of Imago" {Fnt. Rec, iv., pp. 313-315) and the long series of 

 papers on " The Nature of Insect Colours " [Ent. Bee, vi.) ? In this 

 series, Dr. Hiding, Dr. Freer, Kev. C. R. N. Burrows, and others, 

 distinctly proved the existence of the " pigment-factor," which gives 

 us a basis for variation. Then there are " Changes in the Colour 

 of the pupa of Ejiinepliele ianrra just previous to emergence" [Ent. 

 Rec, viii.). " Development of the wing, wing-scales, and their pig- 

 ments in Butterflies and Moths" (Ent. Rec, ix.). "On the wing- 

 scales and their pigment in Lepidoptera " (vol. ix.), " Aberrations of 

 Abra.vaa aylvata [ulinata) " [Ent. Rec, ix.). " The variation of llemero- 

 phila abruntaria'' [E/nt. Rec, x.), and very many other similar papers. 

 One wonders, too, whether Mr. IMansbridge has misled Dr. Mayer's 

 able work. If Mr. IMansbridge has missed all this, is he justified in 

 saying that this particular phase of variation has not evoked the 

 amount of interest its importance warrants? If he has studied these, 

 then we would ask whether, in v ew of the great importance of the 

 subject, Mr. Mansbridge has in any way attempted to till the lacunae 

 that those of us who have done at least something know to exist ? 



When we come to the statements of Mr. Mansbridge's ])aper, one 

 wonders what he means. He sta'es that he considers that ''the 

 variations from yellow or ochreous to red or brown and modifications 

 of theso proceed upon parallel line-! to melanism, and probably arise 

 in a similar way (1) by variation from a commonly-occurring form in 

 the Darwinian sense, (2) by mutations or sudden leaps in the sense 

 enunciated by De Vries." 



On these points we should like to ask a question — In what 

 way does melanism arise ? Mr. Mansbridge gives the answer. 

 (1) *' From a commonly-occurring form in the Darwinian sense." 

 But does not this beg the whole question ? What we want to 

 know is — what gives rise to the commonly occurring form that 

 becomes melanic ? When we know this we shall begin to know where 

 we are. (2) " By mutations or sudden leaps in the sense enun- 

 ciated by De Vries." We should like to have some credible evidence 

 on " sudden leaps " that have achieved the ultimate end of proilucing 

 "melanic" races, "brown" raci'S, or "red" races, from yellow or 

 ochreous specimens arising per aaUiun as aberrations. 



Mr. Mansbridge duly sets "aside the first as more or less affecting all 

 specii s," and then it is stated that " he showa^d how, practically, all 

 definite melanic forms, falling in the second class, of which we have 

 records, have, when first noticed, been of very local occurrence, as the 

 majority still are, a few only having spread, in comparatively recent 

 times, over large areas, and he noted, when this has been the case, that 

 the particular species, e.g., Tei'lmmn binndularia var, delamerensis, 

 Ainp/iidas>/s betidaria var. doubled ay aria, Hybernia maryinaria var. 

 fiiscata and Diurnea fayella black var., are common, and generally 



