NO. I LOCOMOTOR MECHANISMS OF BIRDS — HARTMAN 9 



species with small hearts would have limited endurance. Coturnix, 

 with a larger heart, can sustain the flight required in its long migra- 

 tions. In the domesticated Gallus gallus (white leghorn) the flight 

 muscles and wings are much smaller than in the quail ; otherwise the 

 values are similar. However, the males are much larger than the 

 females and have larger legs (P<o.oi) and hearts (P<o.oi). Our 

 specimens of Coturnix were raised in captivity, but they have not 

 been subjected to selective breeding as has Gallus. 



Numididae. — Numida meleagris, although domesticated, has values 

 similar to those for some of the quails except that the heart is about 

 twice the size and the wings are somewhat smaller. 



Aramidae. — The limpkin {Aramus guarauna), a slow and infre- 

 quent flier, alternating wing beats with sailing, has fairly large flight 

 muscles (21 to 24 percent), wings with a buoyancy index of 3.59, 

 and large leg muscles (16 percent) . Like the rail, he can travel rapidly 

 on the ground. His wings are fairly long (aspect ratio, 2.2 to 2.9). 



Rallidae. — Many rails dive and swim readily but fly feebly, and 

 after a short flight, drop to the ground and run swiftly. Thus their 

 flight muscles are small (12 to 17 percent), and their hearts are 

 moderate in size, ranging from 0.58 to 0.65 percent. In most species 

 the legs are large, especially so in Aramides cajanea (24.8 percent). 

 An immature Laterallus albigularis weighing 20.75 grams possessed 

 a heart 0.70 percent of body, a pectoralis of only 0.61 percent (adult 

 7.0 percent), and lower extremity muscles of 2.51 percent (adult 

 17.4 percent). The flight of the purple gallinule (Porphyrula mar- 

 tinica) ordinarily seems weak and labored, but on long flights it is 

 fairly swift. Both gallinules run with great speed. The coot (Fulica 

 americana) is a more vigorous flier than the gallinules. 



Heliornithidae. — The finfoot (Heliornis fulica) resembles the 

 rail in all his proportions. He swims much and dives to escape, al- 

 though he is a fairly strong flier for short distances. A young female 

 weighing 76.05 grams possessed a heart 0.68 percent of the body, 

 flight muscles only 8.07 percent compared to 17.64 percent for the 

 adult, and lower extremities 9.31 percent of body (adult, 15 percent). 



Jacanidae. — The jagana, which spends much time running over 

 lily pads, swimming if need be, has leg muscles somewhat smaller than 

 those in rails (10 to 12 percent). He hovers much in flying, using his 

 rather large wings (buoyancy index, 3.64). 



Charadriidae. — The plovers are swift runners and strong fliers. 

 Such activity is supported by a large heart (1.36 percent), large flight 

 muscles (29 percent), and lower extremities of moderate size 

 (7.88 percent). 



