492 THE RABF.IT chap. 



nf Eii-^tarhi.-in tube;/?/. Fallopian tulje ; ;,-./•. g.-ill-liKadder ; //./. h.ard palate; 

 //. /'. bones uf hard palate ; //v. hyoid ; i. incisors ; //. ileum ; /. ii. l^a^^a^c of 

 internal nostrik ; /. JaCiilisi.m's orj^an ; /■. left kidney; I. an. left auricle; hig. 

 left llniti, seen throu'..;li |)Ieuia; /t. liver: h'.^. f-iiirth lumbar vertebra; /. rii. 

 left \entriclc: ///. //•. maxillary tnrbinal . //. /. i. nasn-palatine canal; ii.pli. 

 n.aso-pharynx : n . tly. naso-turbinal ; n. s. nas.il septum (middle part cut away) ; 

 ics. gullet; ('/. /. olfactory lobe; OZ'. left o\ ary ; /. a. pulmonary arterj' ; /i^. 

 pericardium; f'tr. g;l. perineal gland; ///. pharjn.x ; ///?'. «. phrenic ncr\e 

 (origin not shown); /. n/.a. posterior mesenteric artery; /. ;//.i-. prema.\illa; 

 //;. pancreas ;/«. rt'. pancreatic duct: pr. c. left precaval ; />. sy. pelvic sym- 

 physis ; //. c. postcaval ; />y. si. pyloric region f>f stomach ; t: ribs ; fct. rectum ; 

 f'..?l. rectal gland ; r. Z'li. right \entricle ; sk. /. door, and .f/r. ^-. roof of skull ; 

 v7. s;L sublingual gland ; .^^ }nx.gl. snbmavillary gland ; s.p. soft palate, ending 

 in the \ elum palati, on the lower side of which a tonsil is seen ; up. c. spinal cord ; 

 xp. )t. spinal (lumbar) ner\es ; .(. t: sacculus rotundas of ileum ; .f. 7'. iirst sacral 

 \ertebra : .¥j'. s)'mpathetic (the anterior end shown on the right side, the rest on 

 the left) : /. tongue; f/i>-. thyr.jid ; //i. 7 ■' ninth thoracic \ertebra : //n'. thymus ; 

 Ir. trachea; ;/./'/. urinary bladder; //;-. ureter; jif. litems; r'17^. \agina: z'i. 

 \estihule : r'4^ \agiis (the anterior end shown on the right side, the rest on the 

 left): Z'„/. NuKa. 



outer margin. The ti>ui:;i(c (/) lies on the floor of the mouth 

 to which it is attached below, its anterior, roundeti end 

 being free : the surface of its posterior part is elevated, and 

 elsewhere — but more particularly on the tip — its covering 

 of mucous membrane is produced into minute, finger- 

 shaped papilliC, on which some of the microscopic organs 

 of taste are situated (compare p. i8o). Taste-organs are also 

 present on a pair (A circtinn'allate papilla, on the dorsal side 

 of the tongue towards its posterior end, and on a pair of 

 transversely ridged areas — the foliate papilla, situated 

 laterally, sliglitly anterior to the former. The main 

 substance of the tongue is composed of muscles, some 

 extrinsic —/.('. arising from other parts, and others in- 

 trinsic — /'.('. entirely confined to the organ in question. 



The Ay/// (l'"igs. i 22 and 123), as we ha^e seen, are not all 

 alike, as in the dogfish and frog : there are incisors and cheek- 

 teeth or grinders, the latter l)eing divisible into two series — 

 the //r///(//(/;'.f and the ///f'/(?/x Inmost Mammals there is 

 also a pair of canine teeth, situated between the incisors and 

 premolars, and these are especially long and pointed in such 

 carnivorous animals as the dog and cat. In the dogfish 

 and froi;, again, the teeth are continuall)' renewed as they 



