Nervous System of Amphioxus 101 



walls of this vesicle contains cells of a similar 

 character to those found in the grey matter of 

 the basal ganglia; they give off sensory fibres 

 which terminate in the epidermis of the anterior 

 end of the animal's body; otherwise an Am- 

 phioxus has no brain. 1 Motor and sensory 

 nerves are given off in pairs from the central 

 nerve cord to each section of the animal's body. 



An Amphioxus is able to swim through the 

 water by sinuous movements of its body; it has 

 no fins, head, or jaws. It habitually rests with 

 the greater part of its body buried in the sand, 

 its anterior end projecting into the water. In 

 this position the animal obtains nourishment 

 from minute organisms, drawn inwards by 

 means of a current of water created by a ciliated 

 apparatus surrounding its mouth. If alarmed 

 the animal buries itself in the sand. 



The class of animals which in the ascending 

 scale succeeds that to which Amphioxus belongs 

 includes the Fishes, which are divided into two 

 main groups : first, those having a cartilaginous, 

 and secondly a bony skeleton; the former are 

 represented by lampreys, dogfish, and sharks; 



1 The Introduction to the Study of the Comparative Anatomy 

 of Animals, by Prof. Gilbert C. Bourne, Vol. II., p. 282. 



