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SCIENCE. 



[N. S. Vol.. XV. No. 385. 



and soldiers of Pheidole species often vary- 

 independently of each other, in both form 

 and coloration and it has long been known 

 that tliis variation is not a correlative one, 

 since the examination of many species has 

 shown that it is impossible from a study of 

 the soldier of a given species to predict 

 the form, sculpture and coloration of the 

 corresponding worker and vice versa. This 

 is beautifully illustrated, so far as colora- 

 tion is concerned, by the Texan varieties 

 of Ph. hyatti Emery. In west Texas (San 

 Angelo, Terlingua, etc.) both soldiers and 

 workers are of a rich fulvous yellow. In 

 central Texas, however, the workers are 

 black or nearly so, whereas the soldiers 

 may be yellow throughout, brown with 

 pale yellow heads, or in other nests nearly 

 or quite as dark as the workers. Not only 

 do the variations among the soldiers be- 

 come nmnerous and considerable only in 

 older nests, but the same is also true of 

 the workers. In large nests of an unde- 

 scribed seed-storing species (allied to Ph. 

 pilifera Roger), I recently found several 

 workers (macroergates) of the size and 

 coloration of the soldiers, but without any 

 tendency to increase in the size of the head 

 or assumption of the sculpture of the 

 soldiers. 



Among the males and virgin queens, 

 which do not make their appearance till 

 the colony is mature — in some species of 

 ants not till the second or third year after 

 the colony is founded— we also find very 

 pronounced variations. These are, of 

 course, more significant, since they occur 

 in individuals undoubtedly capable of re- 

 production. Here we must include the 

 whole range of normal and pathological 

 variations, such as the various transitional 

 forms between the workers and queens 

 (mierogynes, pseudogynes, ergatoids, mac- 

 roergates) and the pathological transitions 

 between males and queens or between males 

 and workers (hermaphrodites, or gynan- 



dromorphs) as well as the normal males 

 and queens of different sizes, structure and 

 coloration. It is a significant fact that all 

 these variations, no matter how aberrant, 

 are cared for and protected in the nest so 

 long as they are capable of being fed. They 

 are enveloped by the general fostering in- 

 stinct which is so characteristic of the 

 worker ants, since it leads to conditions in 

 such marked contrast to the well-known 

 goring instincts of cattle and the weaker 

 but nevertheless perfectly patent analogues 

 among men. The following facts show that 

 the motives for a tragedy like the CEdipus 

 Tyrannus do not exist in ant-society. In 

 one of my artificial nests there is a con- 

 genitally crippled worker of Polyergus 

 bicolor Wasmann that is scarcely able to 

 walk. Still for the past three months it 

 has been carefully fed and cleaned by the 

 workers of the enslaved species (in this 

 instance, workers of two species, Formica 

 suhcenesceus Bmety and P. obscuripes 

 Forel). In the nest of a new species of 

 Leptothorax I have seen a somewhat crip- 

 pled lateral gynandromorph (male on the 

 left side, with testis, worker on the right, 

 Avith ovary ! ) that must have been fed and 

 cared for by the workers as it was perfectly 

 mature. Forel* describes a lateral gynan- 

 dromorph of Polyergus rufescens that was 

 moving in file with the normal workers 

 and carrying a larva which it had pillaged. 

 Here belong also the peculiar parasitized 

 macroergates which I described in a for- 

 mer paper, f These and many other cases 

 that could be cited may perhaps make it 

 easier to understand how monstrous neuter 

 forms like the Pheidole soldiers could 

 develop phylogenetically. 



Several of the above mentioned varia- 

 tions, like the ergatoids and gynamdro- 

 morphs, have not yet been observed in 



* ' Fourmis de la Suisse,' p. 142. 

 t ' Tlie Parasitic Origin of Macroergates Among 

 Ants,' Am. Natur., Vol. 35, 1901. 



