174 



STUDY OF PIG EMBRYOS. 



Next in importance comes the sagittal series, but it is desirable that every stu- 

 dent should have a series in the three standard planes at his disposal for study. 

 In the practical laboratory study each student should be required to make a series 

 of accurate camera lucida drawings of carefully selected typical sections ; then to 



28* 3V0 380 



Fig. ii2. — Reconstruction of a Pig Emisryo of 12.0 mm. with Indications of the Planes of Sec- 



1 IONS FlGi'KI D. 

 an, Cloacal membrane. Ao, Aorta. An, Auricle. A.utn, Umbilical artery, a.v, Vertebral artery, bos, Basilar 

 artery, c, Anlage of oecura. ear, Internal carotid, can, Caudal artery. C.Ex, External carotid artery. 

 f.b, Fore-brain. G, Spinal ganglion, g, Gall-bladder, k.i, Hind-brain. In, Intestine. Li, Liver. 

 m.b, Mid-brain, op, Optic vesicle. Ol, Otocyst. pan. Pancreas. Sp, Spinal cord. Si, Stomach, i'm. 

 Umbilical opening. Ven, Ventricle of heart. ///, IV, I", Aortic arches. 



185 Transverse section, Fig. 1 13 



198 " 



249 



292 •' ' 



321 



470 



513 



633 " 



