Entomological Society. 



8123 



Varieties versus Hybrids. 



" At the March Meeting of the Society, Mr. Fereday read a paper of extreme inte- 

 rest, on variation in the coloration or ornamentation of certain Lepidoptera which he 

 exhibited, and argued that the discrepancy between the specimens in question, and 

 the insect in its normal or typical phase, probably resulted from the male and female 

 being referable to different species, although we all know that it is generally assumed 

 that the male and female progenitors of a moth are invariably of the same species. 

 To such an assumption Mr. Fereday objects that ' we ought not to accept as a fact 

 anything which may be, but is not, established by direct and conclusive evidence.' 

 Without attempting to deny the primd facie value of this axiom, I may perhaps be 

 allowed to state that we accept, on theoretical grounds only, many conclusions that 

 are not susceptible of proof by direct evidence ; and that we shall continue to do so 

 as long as such minds as those of Galileo, Newton and Cuvier are from time to time 

 permitted to enlighten us ; indeed, unless we theorize on very slender knowledge, we 

 shall remain in utter ignorance of much that now passes for sound philosophy. Mr. 

 Fereday proceeds further to support his idea of hybridism by objecting to our forming 

 any conclusions about parentage without positive evidence. These are his ex- 

 pressions: — ' To prove that the so-called " varieties" are varieties and not hybrids, I 

 contend that it is not sufficient to prove their descent from a particular female, but 

 that there must be evidence of the male parent having been an insect of a precisely 

 similar type to that of the female parent ; because, if the male varied from the female, 

 the very question upon which I raise an issue is again involved.' I do not object that 

 Mr. Fereday should lay the onus probandi on those who adopt an opposite theory ; but 

 if this be fair and logical, then a moment's reflection will convince any one that the con- 

 verse is equally fair and logical, and that the onus probandi may also be laid fairly and 

 logically on the advocates of the hybrid hypothesis : for the sake of example : — ' To prove 

 that the so-called " hybrids" are hybrids, T contend that it is not sufficient to prove 

 their descent from a particular female, but there must be evidence of the male parent 

 having been an insect of a species totally distinct from the female parent, &c.' I will 

 further illustrate this : let Mr. Fereday fix on an abnormal specimen of Arctia caja, 

 Abraxas grossulariata, or any otlier, I care not what species, so that it be liable to 

 great variation, and its maternal parentage known, — say a drab caja or a white gros- 

 sulariata, — and then let him find a papa for it in some other species ; it matters not 

 whether totally discordant or closely allied ; thus were he to discover that one of the 

 quakers, as Moses Harris prettily called the Taeniocampse, had been too familiar with 

 the lady tiger, more properly tigress, and that her tell-tale little ones had thus been 

 suffused with drab, or had he detected a Pontia Rapae male, or even a Scoria dealbata 

 male, paying delicate attentions to Abraxas grossulariata female, we could per- 

 haps believe that those nuptially-adorned specimens of the last-named insect resulted 

 from illicit intercourse ; but surely we who believe in varieties, and who call them 

 varieties, are rather hardly treated when we are told that we must prove that these — 

 what shall I call them ? — these eccentricities of genius do not exist. I wish Mr. 

 Fereday to show that they do exist. I am quite sure that if I thought so I 

 should try to prove it, and not lay on the shoulders of another the onus of proving a 

 negative. Tn our domestic animals ((he horse, ox, rabbit, guinea pig, dog, cat, &c.) 

 the coloration or ornamentation varies quite as much as in the tiger or currant moth, 

 and exactly in the same way, that is, in the excess or absence of some particular 



