THE OUTCASTS OF ANIMAL LIFE. 
143 
Tennent of the land-leeches as he saw them in the 
low ranges of the hill country of Ceylon. He tells us 
that these little leeches, about an inch long, fixing 
themselves by their tail suckers, raise their heads in 
the grass to watch for passers by, and as soon as 
they see man or beast they start off. Now stretched 
out at full length, now drawing up the hind sucker 
so as to form a loop, then forward again, they ad- 
vance at an astonishing pace till they reach their 
Land-Leeches of Ceylon * racing to attack some creature. 
victim, when they cling to ankle or leg, or even if 
these are protected are soon up at the neck, where 
they hang in groups like bunches of grapes, as their 
skins swell out with their meal. 
Now, if we wish to learn the secret of the leech 
and how he can move so fast, we must look for it in two 
things, i st, in the muscles by means of which he moves 
his ringed body~; and 2dly, in the chain of nerves 
which give the order for the muscles to move. He 
has three layers of muscle in his skin in the first, 
nearest the outside, the fibres run round and round 
the body in rings,, in the second they cross each 
* Hamadipsa Ceylonica, Sir E. Tennent, Ceylon, vol. ii. 
