136 C. L. TURNER. 



EXPLANATION OF FIGURES. 



Note: All photographs were made from specimens killed and cleared in absolute 

 alcohol and xylol and mounted in balsam. No stains were applied and none of the 

 photographs have been retouched. 



FIG. i. Photomicrograph of the last four segments of a normal 10 mm. larva 

 illustrating the Malpighian tubules (M.P.T.), the heavily chitinized terminal 

 segment (T.S.) and the light dorsal chitinous plates (C.P.). X 24. 



FIG. 2. Photomicrograph of the head of a normal larva illustrating the pig- 

 mented ocellus (Oc.). X 140. 



FIG. 3. Photomicrograph of a normal pupa illustrating the Malpighian tubules 

 (M.P.T.). The pigmented compound eyes are obscured by the dense chitin of the 

 head and thorax. X 80. 



FIG. 4. Photomicrograph of a normal adult male fly. In bringing the Mal- 

 pighian tubules (M.P.T.) into sharp focus the compound eyes (C.E.) were somewhat 

 blurred. X 30. 



FIG. 5. Photomicrograph of the face of a normal adult fly illustrating the 

 pigmented compound eyes (C.E.). The separate facets cannot be made out 

 because of the uniform dense pigmentation. X 120. 



