Peincipal Venous Trunks -^ 



40 



r Carotid supplying the parts aliout the head, including the brain. 

 Peincipal Arterial Trunks J Tulmo-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 portre 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. Teuncus Aeteeiosus laid open to show action of heart — 



Pylangium (Gr. pttle, 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-cutancous, Aorlic, 

 and Carotid trunks. 

 Figs. 3, 4. Cieculation 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. Steuctuee and Framework of the Respiratory 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 cartOages, oue on each side of the glottis, movable inwards and outwards. 

 Laryngo-tracheal 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. 

 Fig, 7. Muscles of the throat for depressing and raising the floor of the mouth — inspiratory muscles. 

 Muscles haying their ( ^ylo-hyoid (Gr. mule, a mill), insertion in rami of mandible. 

 "origin" in anterior 3 Cienio-hyoid, insertion m symphysis of mandible or cliin. 

 portion of Hyoid . . / Hyo-glossus (Gr. glossa, the tongue), insertion in tongue. 

 \ Petro-hyoid, insertion in auditory capsule. 



Muscles having theie "in- ^ ^ i -j //-, ,, , ,, n ... 



„ ( (Jmo-liyoid (Gr. o7nos, the shoulder), origin in scainila. 



SERTION IN posterior V „ ,.,... ho 1 



T-r I bterno-hyoid, origin in sternum. 



portion of Hyoid . . J j > o 



Note.— Tlio point of att-ichment comparatively fixed is called the Origin of the Musele, while the attachment to the part to 1w 

 moveil i.s called its Insertion. 



