No. 419.] MACROERGATES AMONG ANTS. 879 
little fungus-growing ants, Cyphomyrmex rimosus Spinola, which 
abounded on the same hill-slope, and all my bottles and bags 
used for living colonies were filled with these remarkable ants. 
I was therefore compelled to preserve in some small vials of 
alcohol as many of the Pheidole workers as could be captured. 
At the time I supposed that the huge individuals might repre- 
sent some hitherto unknown guest-ant which had taken up its 
abode in the nests of the Pheidole. 
On returning from my collecting trip I found that the con- 
spicuous individuals were nothing more nor less than gigantic 
workers of P4. commutata. One of the nests had yielded six, 
the other three, of these creatures. There were besides from 
each nest two or three somewhat smaller individuals clearly 
intermediate in size between the typical and the gigantic 
workers. All of these large individuals are evidently to be 
regarded as belonging to Wasmann’s category of macroérgates,! 
since they are certainly “ individuals which approach the females 
in an abnormal manner only in the size of the body, but in 
other respects (even in the development of the abdomen) are 
normal workers." Although the abdomen is enormously dis- 
tended in the macroérgates of PA. commutata, it is nevertheless 
clearly of the worker type. 
The length of the normal workers of the Texan PA. commu- 
‘ata is not greater than 3 mm. Many of them are scarcely 
more than 2.5 to 2.8 mm., which was the length of Mayr's 
type specimens from Florida? The largest macroérgates, how- 
Ever, measure 5 mm., while the smaller ones are fully 4 to 4.5 mm. 
long. Thus the volumes of the normal workers and the 
extreme macroérgates would be in the ratio of 27 to 225 if 
they had the same form. But the abdomens of the latter are 
So €normously distended that the ratio must be 27 to at least 
200. In other words, the large macroérgates are nearly eight 
times as large as the normal workers. They are even larger 
than the soldiers, which measure about 4 mm., though in this 
A Pepa E. Die ergatogynen Formen bei den Ameisen und ihre Erklä- 
ge bes Centralbl., Bd. xv (1895), Nr. 16 u. 17, pP- ee D ud 
d. Zoo] cde Die Formiciden der Vereinigten Staaten von Nordamerik 
` - Ges., Bd. xxxvi (Wien, 1886), pp. 419-464. 
