No. 419.] MACROERGATES AMONG ANTS. 881 
in what von Linstow calls the ‘second larval stage,’ which is, 
however, really the immature stage.” 1 
While it is certainly somewhat singular that a species of 
Mermis should occur in ants, even greater interest attaches 
to the case under discussion on account of the manifest effects 
of the parasite on its host. The fact that all the infested 
individuals are of huge size as compared with the normal 
Soh 
dg 
TENA 
7 PLA PST 
ESTANY 
(/ N TAT LEAN ANN 
Ki Were Ny 
Lar ae 
1 
Cann yg 
E 
; Pheidole commutata Mayr. a, normal soldier; 5, normal worker} c, parasitized macroérgate. 
: (Drawn under the same magnification.) 
Workers is remarkable, for, on first thought, one would cer- 
tainly expect an animal infested with such a large parasite to 
be stunted or, at any rate, below the average stature of the 
Species. This paradoxical condition of the macroérgatic Pheil- 
doles is easily understood, however, when we make due allow- 
ance for certain peculiarities in the behavior of ants. In the 
first place it is obvious that the parasites must enter the body 
"Von Linstow, O. Das Genus Mermis, Archiv. f. mikr. Anat. Bd. liii (1898). 
