1907.] WheeJer, The Polymorphism of Ants. 91 



EXPLANATION OF PLATES. 



Plate I. 



Fig. 1. — Pheidole kingi Andre var. instabilis Emery. Soldier, Austin, Texas. 

 Figs. 2-6. — Series of intermediate forms (desmergates) between the soldier and 



worker of Ph. instabilis. 

 Fig. 7. — Typical worker of same. 

 Fig. 8. — Dealated female of Ph. instabilis. 

 Fig. 9. — Male of same. 



Fig. 10. — Orasema viridis Ashmead. Female. Austin, Texas. 

 Fig. 11. -^~ Orasema viridis. Male. 

 Fig. 12. — Orasema coloradensis Ashmead. Female. Colorado Springs, Colorado. 



Plate II. 



Fig. 13. — Phthisergate of Ph. instabilis with very young Orasema viridis larva 



attached to the right side of the prothorax beneath the fore leg. 

 Fig. 14. - — Soldier semipupa of Ph. instabilis with O. viridis larva in second stage 

 attached to the presternal region between the first and second pairs 

 of legs. 

 Fig. 15. — Female semipupa of Ph. instabilis with 0. viridis larva in the second 



stage attached to the pronotal region behind the head. 

 Fig. 16. - — Female semipupa of Ph. instabilis with O. viridis larva in the third 



stage attached to the presternal region. 

 Fig. 17. — Female semipupa of Ph. instabilis with nearly mature 0. viridis larva 

 (shrunken by reagents) attached to the sternal surface between the 

 middle and hind pairs of legs. From a specimen mounted in balsam. 

 Fig. 18. — Female pupa (phthisogyne) of Ph. instabilis with O. viridis semipupa 

 in the pustulate stage, still attached in the position which it occupied 

 as a larva. From a specimen mounted in balsam. 

 Female pupa (phthisogyne) with 0. viridis semipupa in the pustulate 

 stage, still attached to the sternal region. From an alcoholic specimen. 

 Semipupa of 0. viridis, viewed as a transparent object, showing the 

 head, wings, and legs developing beneath the hood-like prothoracic 

 mass. From a specimen mounted in balsam. 

 Semipupa of O. viridis in a more advanced stage. From a specimen 



mounted in balsam. 

 Pupa of female O. viridis just before pigmentation, showing the promi- 

 nent intersegmental abdominal welts. 

 Pigmented pupa of 0. viridis nearly ready to hatch. 



Phthisergate of Ph. instabilis viewed in profile -as an opaque object. 

 From an alcoholic specimen. 

 Fig. 25. — Phthisergate of Ph. instabilis in ventral view to show the greatly atten- 

 uated thorax, small projecting eyes, etc. 



