406 Bulletin American Museum of Natural History. [Vol, XXI ^ 



Owing to the high degree of variabiHty so characteristic of ves- 

 tigial organs, we should expect occasionally to find adult worker ants 

 bearing these structures, especially traces of the larger anterior pair 

 of wings, in a more or less imperfect state of development. And the- 

 probability of finding such workers would seem to be the greater on. 

 account of the vast number of these insects born into the world 

 during every month of the warm season. Among the thousands of 

 workers that have come under my observation during the past six. 

 years, I have, in fact, succeeded in finding four winged individuals- 

 belonging to two colonies of two different species. While this is a 

 very small percentage of the total number of specimens examined, it 

 must be borne in mind that the wing-vestiges are sometimes very 

 minute and easily detached, so that workers actually hatched with, 

 these interesting appendages may rub them off while excavating, or 

 have them torn off by their sister workers while undergoing final 

 ecdysis, or while submitting to the mutual shampooing to which, 

 these insects devote so much of their leisure. 



Sept. 5, 1904, I found at Bronxville, New York, a small colony of 

 a form of Myrmica rubra scahrinodis near the variety schencki Emery. 

 This colony comprised about 150 workers and a dealated female of 

 rather small size. Three of these workers bear vestiges of anterior 

 wings but are in every other respect perfectly normal individuals. 

 In the structure of the thorax there is not the slightest approach to 

 the female type. Each of the three specimens represents a different 

 condition in the development of the wings. In one (Fig. 3) the wing 

 vestiges are nearly 1.7 mm. long, spatulate in outline and very slender 

 at their bases where they are furnished with small but distinct tegulae. 

 The appendages are yellowish brown, translucent and covered with 

 minute hairs like those on the normal wings of females, but without 

 any traces of venation. In another worker (Fig. 4) the wings are 

 barely .4 mm. in length and are merely little opaque pads or sacs, 

 without even a trace of hairs on their surfaces, although they have 

 minute tegulse at their bases. In the third specimen (PI. XIV, Fig. 5) the 

 wings are even more vestigial, the right being represented by a small 

 nodular appendage and its tegula, the left by a minute papilla. In 

 all of these workers the vestiges represent anterior wings, as is shown 

 by their insertion just behind the suture which sharply separates the 

 pro- and mesothoracic segments in the region of the pleurae but not 

 on the dorsal surface. It is very probable that the ants were quite 

 unable to move these appendages. In the dead specimens they are 

 applied to the mesopleuras with their tips directed ventrally and 



