THE FISHES 



169 



than in any of the invertebrates. It also differs in its gen- 

 eral plan from that of most adult vertebrates, owing to the 

 peculiar method of respiration. In almost every case the 



FIG. 105. Angler or frogfish (Lophius piscatorius}. One-tenth natural size. After 



BASKETT. 



vessels returning from all parts of the body unite into one 

 vein leading into the heart, which consists of only one 

 auricle and ventricle (Fig. 106). From the heart the blood 



