Frederic T. Lewis 2^3 



Figs. 3 and 4. Eeconstruction from a rabbit embryo of 8.8 mm., 13 days. 

 Series 465. X 25. 



PLATE II. 



Figs. 5 and 6. Eeconstruction from a rabbit embryo of 11.0 mm., 14 days. 

 This series is not one of the Harvard collection. X 2o. 



Figs. 7 and 8. Eeconstruction from a rabbit embryo of 14.5 mm., 14 

 days, 18 hours (?). Series 143. X 25. 



LETTEEING OF PLATES AND FIGURES. 



The first and last of the spinal ganglia rei^resented in the plates are 

 numbered, the first cervical ganglion being counted 1. 



A. I., intersegmental artery. In each plate only the first and last have 

 been lettered. 



A. M., mesonephric artery. In each plate only one of several has been 

 lettered. 



A. M. S., superior mesenteric artery. 



Ao., aorta 



A. R., renal arterj'. 



A. v., umbilical artery. 



C. M., caval mesentery. 

 !>.* v., duct of Cuvier. 



D. y. A., ductus venosus Arantii. 

 F. W., foramen of Winslow. 



(r. A., g^enital anlag-e. 



Et., heart. 



Ki., kidney. 



Li., liver. (In Plate I the outline of its right dorsal lobe.) 



Lu., ahlage of lung. 



Mes., mesentery. 



M. P., portal mesentery, that part of C. M. caudad to the F. W. 



N., notch between right dorsal hepatic lobe and C. M. 



Fh., pharynx. 



K., position of renal anlage. 



Sp. C, spinal cord. 



(S'. Sc, subcardinal spaces. 



St., stomach. 



U., venous loop throug'h which the ureter passes. 



IJ. y., Urnierenvene (Hochstetter). 



Ur., ureter. 



V. C, posterior cardinal vein. 



T. C. a., posterior cardinal vein, anterior division. 



r. V. p., posterior cardinal vein, posterior division. 

 ■ y. e. m., vein extending into C. M. 



V. dv., vena cava, hepatic portion. 



y. H. C, vena hepatica communis. 



y. L. T. P., posterior transverse lumbar vein. 



T. Hi., small vein running into mesentery. In the plate similar ones, 

 caudad, are not lettered. 



V. m. X., vein running into mesentery and anastomosing with those of 

 the opposite side. 



V. O. 31., omphalo-mesenteric vein. (Portal vein.) 



y. P., portal vein, entering the liver from the M. P. 



V. P., renal vein. 



