PLATE V. 



Figs. LXI-LXII. Sections through the first and second maxilla. 



Fig. LXIII. Transverse section of an older embryo through the first maxillae. 

 It is closed dorsally by mesoderm; beneath this lie the blood cells. 



Figs. LXIY-LXX . Transverse sections of the thoracic region Body wall 

 completed dorsally by mesoderm ; the amnion is incomplete. 



Fig. LXVI. Longitudinal section of ovarian tube of fly; CB'-CB n represent 

 sections of successive chambers of the tube. 



Fig. LXVII. Longitudinal section of a more advanced terminal chamber (C IV ). 



Fig. I. XVIII. Longitudinal section of a more advanced terminal chamber (C IN ) 

 showing elongated epithelium (OYE) excreting chorion (CH) and germinal vesicle 

 (GV). 



Fig. LXIX. Transverse section of terminal chamber at same stage as pre- 

 ceeding through germinal vesicle (CV) and germinal spot (CS). 



Fig. LXX. A longitudinal section of terminal chamber showing germinal 

 vesicle (GS) without boundary. 



Fig. LXX'. Portion of same section more highly magnified. 



Figs. LXXI LXXIV. Sections through the cesophageal region of a spider em- 

 bryo showing amniotic folds (AM) on each side of the supra-cesophageal ganglion, 

 the outer limbs of which in the most posterior section (Fig. LXXIY ) have united. 



