GG SUBSTITUTION OF A WING FOR A LEG IN A MOTH. 



It may not be known to some of those present, as was the case 

 with myself when I first described this specimen in the Ent. Monthly 

 Mag. (vol. xxv., p. 289), how exceedingly rare it is, apparently, 

 indeed, an unknown thing to find one organ or limb substituted 

 for another in the animal kingdom, and it therefore behoves those 

 who come across such an instance to be very careful how they 

 record it. 



The coloured drawing which Mrs. Richardson has made of this 

 moth, which is represented on the accompanying plate, was 

 shewn by Mr. McLachlan at a meeting of the Eutom. Soc. 

 of London lately, and he tells me that it excited great 

 interest, and that no one had heard of such an anomaly. 

 I have since heard from a correspondent who was present 

 on the occasion that it was considered so extraordinary that 

 many thought there must have been a mistake made. It is by no 

 means the first time that this simple explanation has been offered 

 as the solution of a difficulty which was not easily to be understood; 

 but, fortunately, my specimen is in existence, though, being such a 

 precious article, I do not like trusting it to the post. 



I have had some very interesting correspondence with Professor 

 Windle, of Queen's College, Birmingham, a student of teratology 

 (or the science of monstrosities), but amongst the vertebrates only. 

 He tells me that he does not know of much teratological work 

 having been done on invertebrates. He says "Amongst verte- 

 brates the presence of an additional limb, or pair of limbs, is not 

 amongst the great rarities of teratology. Especially it is common 

 amongst fowls, and then concerning the pelvic limbs. It has even 

 been observed in the frog." " These additional limbs, however, 

 are always of the same nature as the adjacent limb, except in cases 

 of marked duplicity. Thus there may be a hand or arm projecting 

 from a sacral tumour near the thigh. Here, however, we have to 

 deal with a different state of affairs, since the tumour and limb 

 represent the ill-developed second half of a double monster. I 

 fancy a leg may be found adjacent to the upper extremities under 

 similar conditions." 



