VARIATION IN LEPIDOPTERA A CRITICISM. 85 



distributed so that transported specimens could easily continue their 

 race wherever they might be carried." 



One learns from this not over-clear statement, that the melanic forms 

 noted by Mr. IMansbridge, fall in his second class, i.e., that the T. var. 

 delaiiwrensis, A. var. iloiihledayarla, ii. var. f areata, and /). fa/jclla black 

 var. have arisen by "mutations or sadden leaps," We should like to know 

 whether Mr. Mansbridge has any evidence that any of these varieties 

 originated by sudden leaps, and whether he thinks the statement "that 

 all definite melanic forms . . . have been, of local occurrence, when 

 first noticed," is satisfactory or suflicient evidence of the assumed facts? 

 We wonder whether Mr. Mansbridge would be surprised if lepidopterists 

 wanted more definite data before accepting such a sweeping generali- 

 sation that these varieties originated by " mutation," as understood 

 by Mr. Mansbridge. We are under the impression that we first 

 collected together the earliest notices that appeared on the variation of 

 these melanic forms in our work Melanism mid Melanochroism in Britis/i 

 Lepidoptera, pp. 8 et secj. (particularly pp. 12-17), and, as we are not 

 aw^are of any earlier record than these, we assume that Mr. Mansbridge 

 has based this generalisation on the facts as there stated, or the same 

 obtained elsewhere. If there are other facts known to Mr. Mansbridge 

 and not to us, our opinion might, of course, be considerably modified, 

 but, if not, then Mr. Maurfbridge appears to us to be making a 

 marvellous assertion on very slender and treacherous grounds. 



Again, if these forms have all increased by sudden leaps (" muta- 

 tions "is evidently the correct thing!), how does Mr. Mansbridge 

 explain the intermediate forms that we have seen in abundance of 

 both sexes of Tephrosia crepn^cidaria (Mr. Mansbridge's T. biiindiilaria), 

 Hijbernia iiiavj/inaria, and Diitrnea fa(/ella. Does Mr. Mansbridge 

 really think the specimens of these species are either ochreous or 

 black ? If so, he cannot know much of the species ? If not, well, 

 then, where does the Kangaroo habit come in ? 



Also, if these melanic species, as Mr. Mansbridge asserts, have been 

 formed by leaps (" mutations "), bow does he explain the necessity of 

 " transported specimens" to " easily continue their race wherever they 

 might be carried " ? Surelj' " black specimens " can leap into exist- 

 ence as well at one place as another, and, this being granted, the carrying 

 is superfluous. We may note, too, that " carrying" is a good term for 

 the means of spreading $ s of Diiimea fngella and Hubernia niar(jinaria ; 

 as we know them these might want much carrying. 



Having given us the opinion that these particular melanic races 

 are the result of " mutations," we come to the general statement, that 

 Mr. Mansbridge " broadly classes all instanci'S of melanochroism, and 

 leucochroism as Darwinian variations," and " all cases of melanism 

 and albinism as well as yellow to rel, or red to yellow, and similar 

 changes where the break is sudden, as mutations or De Vriesian 

 variations." 



Leaving De Vries out of the question, we wonder what this means. 

 Are all the slightly shaded, much shaded, completely fuscous, and black 

 specimens of Hubernia manjinaria, melanic, and all equally the result 

 of leaps, just as far as the individual specimen has got, or are the 

 intermediate ones produced " as Darwinian variations " (!) whilst the 

 uttermost ones are produced by " mutations "'? If this is the idea, we 

 wonder how it is done. 



