52 W. MILNE ON THE 



their habitat is in rushing water, seems to indicate that a 

 plentiful supply of oxygen is necessary. 



The shape is variable ; even when creeping it may keep the 

 trunk fairly stout, or may attenuate it to a very considerable 

 degree. 



M. falcatus has two methods of progression. It has the 

 ordinary leech-like manner of creeping, when it takes a very firm 

 hold with the rostrum, draws up and plants the foot with a rabbit- 

 like hop, and then shoots forward the head again. Its speed is 

 by no means great, and in the open it usually takes but one or 

 two hops at a time, then squatting on two, or it may be four toes, 

 it keeps on swaying the head only, up and down and all round in 

 a restless way, with the cilia of the corona and rostrum vibrating 

 energetically, and the jaws in motion. It can also proceed by 

 swimming, but in a rather helpless rolling sort of way. It aids 

 the effect of the cilia by contractions of the body, and even then 

 the motion is little more than visible. In its habitat, where the 

 water flows swiftly, its power of swimming would be practically 

 useless to it when dislodged from the moss. 



It seems to be most at home when creeping about in the moss. 

 It hops from branch to branch, the head searching tirelessly all 

 about. Every now and then the rostrum is pushed hard against 

 the moss, when with a decided snap it may be successful in 

 breaking off some particles ; it then bends the rostrum down over 

 the corona, and thus with the aid of the cilia, which vibrate 

 furiously, guides the food towards the oral entrance. Frequently 

 when exploring the moss, it jerks back its head at the most un- 

 expected times, a most irritating habit, which also characterises 

 the Adinetae, whose manner of feeding is somewhat similar. It 

 is a great gymnast and seems to enjoy itself most thoroughly 

 when, attached by perhaps two toes high up on the rubbish, it 

 happens to throw its head and body out into the open. It 

 squirms and contorts itself into most fantastic shapes, without 

 the least impression on the foothold. The muscles of the toes 

 and the robust foot are so powerful that it can maintain itself for 

 any length of time, straight out and tense — with no support 

 but the toes — notwithstanding the extraordinary contortions of 

 neck and trunk indulged in ; and quivering all the while with 

 excitement and pure pleasure. At times it sways round with 

 the toes as a pivot, and without the slightest sagging in the general 



