1928] 
Notes on three Abnormal Ants 
51 
NOTES ON THREE ABNORMAL ANTS 1 . 
By W. S. Creighton 
Abnormalities in ants appear to fall into three fairly well 
■defined categories, viz.: (1) sex mosaics and intersexes, (2) 
aberrant forms produced through altered food supply, (3) freaks. 
To the first group belong the various kinds of lateral mosaics 
as well as the rarer anterio-posterior type. The latter often show 
characteristics which mark them as intersexes rather than true 
mosaics. The second group is composed of a large number of 
peculiar forms which arise from pronounced nutritional irregu- 
larities. Lack of food may produce dwarf individuals in all three 
castes, while loss of food due to the presence of parasites gives 
rise to pseudogynes or the shriveled victims of Orasema. In the 
event of an overabundance of food unusually large males and 
females, egg-laying workers and, more rarely, repletes may result. 
It is impossible to draw any hard and fast line between the mem- 
bers of this group and those forms considered normal since in 
many cases conditions which originally must have been quite 
aberrant have, in time, become an integral part of the life of the 
species (e. g. the repletes of Myrmecocystus or the microgynes of 
certain Formicas). In the third group may be included those in- 
dividuals which show duplication, loss or malformation of parts. 
Most of these conditions seem to be due to injuries in the larval 
or pupal stages. More rarely the changes are of an atavistic 
nature. Many of the members of this group are veritable en- 
tomological nightmares, monstrosities with double scapes or 
legs; fantastic creatures with shortened and twisted antennae 
and limbs or misshappen thoraces; freaks without eyes, or lack- 
ing tarsal, antennal, rarely even petiolar joints. 
In this paper are described three abnormal ants, two freaks 
and an ergatandromorph. Both freaks are in the collection of 
Dr. Wheeler through whose kindness I am enabled to describe 
them. It is therefore my pleasure to thank the donors for their 
Contributions from the Entomological Laboratory of the Bussey Insti- 
tution, Harvard University, No. 291. 
