132 



PROCEEDINGS OF THE ACADEMY OF 



[Feb., 



the body in being unbranched. These hairs are secreted by large 

 hair-mother cells which lie among the outer pigment cells between 

 the ommatidia, and their development is of interest on account 



Fig. 4. a. Hair cell of young pupa, showing three nuclei and intracellular 

 duct. b. Cross-section through pupal retinulse, showing one hair cell. c. Cross- 

 section through hair just at level of cones, showing structure of intracellular 

 duct. d. Cross-section distal to c and beyond surface of eye. e. Older pupa 

 hair cell. /. Hair cell of adult, showing relation to cone and lens. 



of the presence in them of an intracellular duct and because of their 

 binucleated condition. In the larval eye these hair cells cannot be 

 definitely located, but there are certain large cells with peculiar nuclei 



