KlG. 17. Transverse 

 i head of normal I 

 is; cerebellum 

 medulla, pharynx. 

 Compare with PI. .\ 

 at medulla). Kor oih--i 

 under I'l. I. fif{. i. { ij.) 



Cerebellum 

 Cavity ventricle IV 

 Periotic cartilage 

 Semi-circular canal 

 Utricle 



Ganglion nerve VIII 

 Saccule 



Hyomandibular 

 - Notochord and 

 Rectus oculi externus (origin) 

 Visceral arch III 



,, IV 



,, V 



Pharynx 

 Truncus arteriosus 



Cavity ventricle IV 



Medulla oblongata 



Parachordal cartilage - 



[Notochord 

 Ganglion vagus 

 Jugular vein 

 Aorta 



Aortic arch III 



Visceral arch III 



Visceral arches IV, V. 



Visceral arch VI 



r Auricle 



Cartilage pectoral^girdle.. 

 Ventricle 



KlG. 18. Transverse section 



through head ot norms! trout embryo, 



>ij the posterior part of the 



e gill chaml*-rs, and the 



if the heart. Compare 



11 at optic 



i- I'. ... : '.. .r ;; . 



nml trout embryo 



The section passe*, through the head- 

 kidney, oesophagus, and pectoral fin. 

 Other references under PI. I. fig. i. 



Spinal cord 

 Neural arch cartilage 

 Notochord 



- Haemal arch cartilage 

 . Aorta 



Wolffian body 

 Wolffian duct 

 Posterior cardinal vein 



. Oesophagus 



- Pectoral fin 

 . . Yolk 



Spinal cord - 

 Notochord (double) 



Wolffian duct - 



Posterior cardinal vein - - 



Swim-bladder 



Pancreas 



Intestine - 



Yolk - 



FIG. 20. Transverse section of nor- 

 mal trout embryo, across middle of 

 body, showing swim-bladder, intestine, 

 and pancreatic tissue. The specimen, 

 which is otherwise normal, shou 

 reduplication of the notochon I 

 p. 54. Other references mid 

 fig. i. (xi5.) 



J. F. G. 



PI.. IV. 



IV 



