116 KAMBLES OF A NATURALIST. 



manifest. The body is a mere sac, in which there 

 lies immersed a nearly straight intestine ; here are 

 no internal partitions and no circulatory organs, the 

 liquid, which represents the blood being moved only 

 by bands of vibratile cilia, which are placed in a 

 slanting position upon the base of each foot. 



But if we would observe the extreme limit to 

 which degradation of type may attain in the Articu- 

 lata, we must descend to the class of Worms, properly 

 so-called. Here great size is often associated with 

 extreme simplicity of organisation ; a circumstance 

 which is nowhere else exhibited in so high a degree, 

 not excepting even the Eadiata. The Nemertes 

 Borlasii presents a remarkable instance of this.* 

 Figure to yourself an animal from thirty to forty feet 

 in length, and only five or six lines in width, flat as 

 a riband, of a brown or violet colour, and smooth 

 and shining as varnished leather. Such is the 

 Nemertes, whose anatomy had never before been 

 studied, although the animal had been long known. 

 This gigantic worm lurks under stones and in the 

 hollows of rocks, where it may be met with rolled 

 into a ball and coiled into a thousand seemingly in- 

 extricable knots, which it is incessantly loosening and 

 tightening by the contraction of its muscles. This 

 animal is nourished by sucking the Anomia, a kind 



* The Nemertes constitute a numerous and interesting group ; 

 and I have devoted considerable time and attention to their study. 

 The species referred to in the text is the Borlasia Anglice. Fisher- 

 men state that they have seen these animals more than a hundred 

 feet long. 



