148 GLIMPSES OF NATURE. 



to the fixity of the plant ? are queries at the mere 

 mention of which, I am sorry to say, scientists will 

 not repress a grim sarcastic smile. If you hold that 

 it is an animal because it moves, then what are you 

 to say to the fact that thousands of the lowest plants 

 are never rooted and fixed at all ? 



And what, further, will you reply to the observation 

 that many true animals are rooted and fixed through- 

 out life ? There are your sponges, your anemones, 

 your corals, your zoophytes, and your sea-squirts, all 

 of which are fixed creatures but true animals, never- 

 theless. So that you observe the mere fact of motion 

 does not prove that a living being is an animal ; and 

 it certainly does not disprove the assertion, contrari- 

 wise, that it may well be a plant. 



The volvox before us is, in truth, an excellent 

 illustration of the difficulty which attends us when we 

 attempt to distinguish animals from plants. Not that 

 it is difficult to separate higher animals from higher 

 plants. There is no danger of confusing a cow with 

 the grass it eats ; but, then, there are other and much 

 lower animals in the world than cows, and many 

 plants lower than the grass. When we face a living 

 being like our volvox, we see the greater difficulty 

 which arises that of saying in which kingdom of 

 living nature we are to put the lowest members of the 

 world of life. 



Now each of the green specks in the volvox might 

 be an animal, and each might be a plant. Because 

 the specks are green, and because they make starch, 

 are facts forming no barrier to their being animals ; 

 for many true animals (like the " hydras " of the pools) 

 manufacture the same green colouring matter we find 

 in plants ; and many animals, including even man him- 



