248 POND LIFE. 



and habits of life are almost unlimited. So that it is quite imposs- 

 ible for me to-night to do anything more than give you a short 

 account of one or two prominent forms, and I shall try to select 

 those which illustrate points of general interest. 



There is one little creature^ of an ovoid form, called Eiiglena 

 virldis, which you may find swimming about by means of a long 

 hair-like process at one end of its body, and provided with a red 

 spot either at one end or the other, which for a long time was 

 described as an eye. Whether it be so or not is a matter which 

 can only be settled by the most accurate observations, and as the 

 creature is exceedingly minute, and very active, these are very 

 difficult. As it moves, it twists round and round on the long 

 axis of its body, with a curious wabbling motion, and by very 

 close observation you may see that it has a long, fine hair 

 projecting in front, and somehow or other it is by its means that 

 the creature progresses, although it is rather difficult to see exactly 

 how this takes place. 



There are a good many different forms of these Eiiglejice. Some 

 are long and narrow, and others are short and broad. They illus- 

 trate one group of the Infusoria^ characterised by having one long 

 hair-like process, whence they are known as Flagellata. 



There is another group, characterised by having a round body, 

 which is generally stalked, and by a number of tentacles projecting 

 in all directions, which when examined are seen to possess little 

 sucker-like knots at their extremities. By means of these they 

 catch their prey; suppose, for instance, that a small organism 

 happens to come in contact with one of these little tentacles, it is 

 instantly seized upon, and the small knobs flatten themselves out 

 and suck the juices out of the prey, which may be another 

 I?ifiisoria7t, or perhaps one of the small water-weeds {Algce). 

 Generally two or three tentacles come to the assistance of the 

 one which first captures the food, and bring their suckers also to 

 bear upon the captured organism. 



We have now considered two groups of Ijifiisoria, one provided 

 with a long cilium and another having a number of suckers. 

 There is still another group, characterised by having a large num- 

 ber of these fine hairs or cilia. If you take a piece of weed from 

 one of our ponds, you are very likely indeed to find springing from 



