234 



HITCHCOCK'S ANAT 031 Y 



414. Arteries — Wonder Jiets. — The trunk of the aorta is 

 very short, and after giving arteries to supply the heart it di- 

 vides at once into two large branches, quite unlike the con- 

 formation in mammalia. Wonder nets, too, are often found 

 in birds, and especially in those arteries supplying the brain, 

 eyes and legs. 



Fig. 232. 415. Blood —The blood of 



birds has the highest tem- 

 perature of the vertebrate 

 animals— 110° F. The blood 

 cells, or corpuscles, are al- 

 ways of an elliptical form and 

 of a very uniform diameter. 

 416. Heart of Reptiles. — 

 The heart of reptiles ordinarily consists of a single ventricle, 



B 



0) 



Pigeon's Blood (red) Corpuscles Magni- 

 fied 400 Diameters. A, In Natural State. 

 B, Altered by Acetic Acid. 



FlG. 233. 



Fig. 234. 



Blood Corpuscles of the Frog, 400 Diameters. 

 A, In Serum. <7, F ully Developed. I, Nucleus 

 with clear contents. 



or propelling cavity, and two auri- 

 cles, or receiving cavities, so that 



Circulation in Reptiles, a, Heart, the pure blood 19 mixed with the 

 b, Ventricle, c, c, Auricles. impure (or a portion of it) aS it 



comes from the lungs, which accounts in part for the general 

 sluggishness of these animals. The blood corpuscles of rep- 

 tiles are large and oval, as may be seen in Fig. 234. 



414. Into how many branches does the aorta at once divide ? Where are wonder nets 

 found in birds? 415. What is said of the temperature of birds? What of blood-cells ? 

 416. Describe the heart of reptilea. What is the effect upon the blood? What is the 

 size of their blood-vessels ? 



