40 



PRINCIPAL VENOUS TRUNKS < 



( Carotid supplying the parts about the head, including the brain. 



PRINCIPAL ARTERIAL TRUNKS 1 Pulmo-cutaneous supplying the lungs and dorsal integument. 



(. Aortic supplying the rest of the body. 

 'Superior cava returning blood from the head, forelimbs, and 



dorsal integument chiefly. 



Pulmonary veins returning blood from the lungs. 

 Vena portoe returning blood from the stomach, intestine, spleen 



and pancreas to liver. 

 Anterior abdominal returning blood from the urinary bladder 



and belly- walls to liver. 



Inferior cava returning blood from the hind-limbs, kidneys, and 

 liver chiefly. 



DIAGRAM II. TRUNCUS ARTERIOSUS laid open to show action of heart 



Pylangium (Gr. pule, gate ; angeion, a vessel), or receiving part, contains a median longitudinal 

 valve or movable partition attached to the dorsal surface, and a small transverse valve on the 

 right side. 

 Synangium (Gr. sun, together), or distributing terminal part, gives rise to Pulmo-cutaneous, Aortic, 



and Carotid trunks. 

 FIGS. 3, 4. CIRCULATION OF THE BLOOD IN THE WEB 



Arteries with flow of blood towards the smaller branches. 



Capillaries arising from the ultimate branches of the arteries and giving rise to the veins. 

 Veins with flow of blood from smaller to larger vessels. 

 Oval blood-corpuscles coursing through the vessels. 

 Pigment-cells on the surface 

 RESPIRATORY SYSTEM 



FIGS. 5, 6. STRUCTURE AND FRAMEWORK of the Piespiratory Organs 



FIG. 5. Glottis (Gr. glotta, the tongue), a longitudinal slit opening into the floor of the back part 



of the mouth or pharynx (PI. XVIII. Fig. 3). 



Arytenoid cartilages, one on each side of the glottis, movable inwards and outwards. 

 Laryngo-trachcal cartilage, a ring forming the very short tube common to the two lungs. 

 FIG. 6. The Lung is a thin-walled, elastic, and transparent bag, the inner surface of which 

 shows shallow depressions produced by infoldings of the wall, and corresponding to the air- 

 cells of higher animals. 

 MUSCLES of the throat for depressing and raising the floor of the mouth inspiratory muscles. 



( Mylo-hyoid (Gr. mule, a mill), insertion in rami of mandible. 

 MUSCLES HAVING THEIR I /,./.,. ,. . , . , ,.,, , 



i Gemo-hyoid, insertion in symphysis of mandible or chin. 

 "ORIGIN" IN ANTERIOR -< TT , J . . .. 



) Hyo-glossus (Gr. glossa, the tongue), insertion in tongue. 



^ Petro-hyoid, insertion in auditory capsule. 



FIG. 7. 



PORTION OF HYOID 



MUSCLES HAVING THEIR "IN- 

 SERTION" IN POSTERIOR 

 PORTION OF HYOID . . 



^ ^ , ., , , ,, \ ... 



I Omo-hyoid (Gr. omos, the shoulder), origin m scapula. 

 }. , .j ... 

 1 Sterno-hyoid. origin in sternum. 

 ) 



NOTE. The point of attachment comparatively fixed is called the Origin of the Muscle, while the attachment to the part to Iw 

 moved is called its Insertion. 



