REFERENCE LETTERS. 



Am. Amnion. 



Am. F. Amniotic folds. 



Am. Portion of amnion folds which 



forms dorsal surface of body. 

 App. Thoracic appendages. 

 BL. Blastoderm. 

 BH. Blastopore. 

 C". Sub-oesophageal commissure of su- 



pra-oesophageal ganglion. 

 C'. Supra-cesophageal commissure of 



supra-oesophageal ganglion. 

 C. Circum-oesophageal commissure. 

 CB. Chambers of ovarian tube of Fly. 

 CH. Chorion. 

 E. Embryo. 



E.' Vesiculated portion of yolk. 

 EC. Ectoderm. 

 FE. Folicular epithelium. 

 GL. Salivary gland. 

 GV. Germinal vesicle 

 GS. Germinal spot. 

 H. Heart. 

 I. Inner layer. 

 I'. Migratory cells of inner layer. 



IS. Somites of inner layer. 



le. Endodermic portion of inner layer. 



LB. Labrum. 



LB. N. Labial nerve. 



M. Muscle. 



MD. Mandible. 



MX. Maxilla. 



MX'. Second maxilla. 



MXL. Maxillary lobes. 



NS. Nervous system. 



NC. Nutritive cells. 



OVE. Ovarian epithelium. 



PC. Procephalic lobes. 



S. Cuticle. 



YC. Yolk cell. 



YB. Yolk ball. 



YS. Yolk spherule. 



YS'. Homogeneous yolk mass. 



No. I. Anterior portion of supra-oeso- 

 phageal ganglion. 



No. I'. Posterior portion of the same. 



No. II. Mandibular portion of sub-osso- 

 phageal ganglion. 



