IV 



IM.3I 



N.2I. 



N.6 



FiG. 227. Diagrammatic figure of a Human Embryo, lettered by Professor 

 His, Ko, and estimated as thirty-one days old. The brain and spinal 

 cord, and the cranial and spinal nerves are shown, and certain of the other 

 organs are represented in outline. The bases of the fore and hind limbs 

 are indicated by the dotted outlines. In all cases in which the full length 

 of the nerve is not shown, the end is represented as though cut across. 

 (After His.) x 10. 



BF, thalamencephalon. BM, mid-brain. BS, cerebral hemisphere. B Y, olfactory 

 lobe. El, auditory vesicle. FG-, Froriep's ganglion. GC, ciliary ganglion. TTTVf , 

 hyomandibular cleft, or external auditory meatus. N.I, ganglion of first cervical nerve. 

 IsT .9, ganglion of first thoracic nerve. M".21, ganglion of first lumbar nerve. M".26, 

 ganglion of first sacral nerve. W.31, ganglion of first coccygeal nerve. If H, phrenic 

 nerve. OC, optic cup. OF, olfactory pit. RB, left auricle. RV, ventricle. STJ. 

 siim.s prascervicalis. TI, vitelline loop of intestine. TL, tail. ~W, liver. Ill, third 

 cniuial nerve. IV, fourth cranial nerve. V, Gasserian ganglion. V, ophthalmic 

 branch of fifth, or trigeminal nerve. V&, maxillary branch of fifth, or trigeminal nerve. 

 Vc, mandibular branch of fifth, or trigeminal nerve. VII, ganglion of the seventh, or 

 facial nerve. VIII, ganglion of the eighth, or auditory nerve. IX, ninth, or glosso- 

 pharyngcal nerve. X, ganglion of the root of the tenth, or pneumogastric nerve. XI. 

 roots of the eleventh, or spinal accessory nerve. XII, roots of the twelfth, or hypoglossal 

 nerve. 



M M 



