VI FORM AND FUNCTION 85 
Fic. 25.—Diaphragm of Duck (diagram after Strasser). ‘The sternum has 
been removed. 
Abs, abdominal sack ; it runs back under the viscera and opens into the lung; 
sometimes penetrates the pelvis and femur: as, anterior thoracic sack s, axillary 
sack, a pouch of the interclavicular ; cs, cervical sack ; D, diaphragm ; G, gizzard ; 
GP, great pectoral muscle turned back; H, heart; 1, intestine; 1cs, interclavicular 
sack, often p:n-trates keel ; Lg, lung ; tg’, line to which the lungs reach ; Ll and Lr, 
left and right lobes of liver ; ps, posterior thoracic sack ; T, trachea. 
