ON SOME ABNORMALITIES IN ANTS. 81 



Oil some Abnormalities in Ants. 



(With Plate II.) 

 By HORACE DONISTHORPE, F.Z.S., F.E.S., Etc. 



In 1917 the late H. Viehmeyer published a short paper on abnor- 

 malities in the skeleton of ants, embracing certain cases of malforma- 

 tion, variability, intermediate forms, and gynandromorphism, which 

 had come under his observation in the course of time [Hntoin. Mitt.,6f 

 66-72 (1917)]. 



The first category included a ( 'aniiioiintiifi {Dinorni/rmex) i/iijas, Latr., 

 cf , with a projection proceeding from the inner side of the left fore 

 tibia, which he regarded as a second half tibia ; an Overbeckia snhcla- 

 rata, Yiehm., (^ , with a deformed thorax; specimens of C((nipnnotiis 

 raf/aiia, Scop., $ , and i'orniici I'vattims, Retz., ? , with deformed 

 scales, etc. 



The second category included certain variations in the scales of 

 Cniiilio)iiitiis (^Mi/iDtotiirha) iiiacidatiis-c/doroticiis, Emery, J , b'orinica 

 rufa, L.. 5 , and /''. pratenaiK, Retz., 5 ; and of the petiole in Mj/nnica 

 [Xeinin/)-}ii(i) nibida, Latr., 5 ^ . 



The third category consisted of Mijnnica brrz/i, Ruzsky, var. 

 harc/uoiicii, Ruzsky ^ , and Mijiinica nii/ino'lis, Nyl., var. rntii)iodo- 

 laeriiiolis, Forel. This from the description is evidently a Pterergate. 

 The fourth an ergatandromorph of Mi/niiicct rtif/iiiosn, Nyl. 



I have for some time past been collecting similar cases to those 

 recorded by Viehmeyer ; and am here describing and figuring a certain 

 number which come into the first two categories. 



As the third and fourth belong to phenomena of quite a different 

 nature, I do not propose to deal with them in this paper. 



No. 1. (Fig. 1.) Mi/rniira ii(ifiito(]is, 'tiyl., ^, taken at Wey bridge, 

 July 2iSth, 1919. This ant was walking about on the heath, and 

 although to the naked eye it appears to be normal, yet there was some- 

 thing about its movements which caused me to bottle it. Under the 

 microscope there can be seen a short growth projecting from the l)asal 

 third of the inner side of the scape of the left antenna; a tiny point 

 occurring at the end of the projection. It may possibly be a portion 

 of a half-formed second scape ; the point at the end being the spot 

 whence the funiculus would arise. This growth may be due to an 

 injury, caused by pressure or otherwise, in an earlier instar ; the wound 

 l)eing the starting point of a super- regeneration of a second scape. As 

 pointed out by the late Dr. Chapman in a paper on some experiments 

 on the regeneration of the legs of Liparis dispcir, L. — "Where crushing 

 takes place and possibly, therefore, division of the group of embryonal 

 cells that provides for regeneration, there may take place various sup- 

 plementary portions, branches, and duplication of limbs." [Tra)is. 

 hit. Hilt. rmuj. (h-fhi-d, 2, 805 (1912).] 



No. 2. (Fig. 2.) Mi/niieciiia ifrauiinio)l(i,hi\tv., '^ . Both antenna? 

 are deformed, being bent and curled round like a ram's horns ; other- 

 wise it is perfectly formed. This may be the result of some injury, but 

 I am more inclined to think that the pupal skin had not been properly 

 removed from its antenuio by its fellow workers when it was a callow. 

 The result being that thev had liecome stiff and fixed in one [)ositioii. 



May IflTir, ]02*J. 



