DESCRIPTION OF FIGURES" 

 The structures shown in the following figures are designated by numerals: 



Figures 1 to 13, inclusive, represent reconstructions of the arteries, veins and 

 lymphatics found in the regions of the head and pharynx in the embryos of the 

 trout (figs. 1 to 11, inclusive) and Amia (figs. 12 and 13). The arteries are shown in 

 red, the veins in black and the lymphatics in green. The vascular system of the 

 trout embryos (figs. 1 to 11, inclusive) and that of the 10 mm. embryo of Amia 

 (fig. 12) were reconstructed after the method of Born, at a magnification of 200 

 diameters; while that of the 19 mm. embryo of Amia (fig. 13) was reconstructed 

 after the method of Born at a magnification of 138 diameters. In order to display 

 the smaller reconstructions to the best advantage, a uniform reduction has not 

 been followed in reducing the size of the figures in the plates. 



PLATE 1 



EXPLANATION OP FIGURES 



Figs. 1-2 Lateral view of the arteries, veins and lymphatics found on the left 

 and right sides, respectively, of the head and pharynx in a fourteen-day steel head 

 trout embryo; injected embryo. P. E. C. 7 696. 



REFERENCES 



1, Subocular lymph sac. 8', Caudal end of otocyst 



3"', Cardino Cuvierian lymph sac; 11, Postcardinal vein 



anlage of the lateral pharyngeal lym- 12, Duct of Cuvier 



phatic which may arise opposite to 14, Dorsal aorta 



the cardino-Cuvierian junction or be- 15, Hyoidean artery 



tween the latter and the otic lymph 20, Caudal end of eye 



sac 22, Carotid artery 



6, Precardinal or jugular vein 23, Infraorbital vein 



8, Cranial end of otocyst 



6 The photomicrographs (except fig. 41) were made by Mr. C. F. Silvester, 

 and figures 1 to 13, inclusive, were drawn from reconstructions by Mr. Anthony 

 J. Walter. 



7 Princeton Embryological Collection. 



76 



