14 AN INTRODUCTION TO ZOOLOGY. 



class in biology demonstrates, with a bit of gamboge, 

 how very closely the Brownian movements — mechanical 

 gyrations executed by minute particles of matter — may 

 appear to resemble the gyrations of living organisms. 

 But even those who have mastered the difficulties of 



'-a 



a 



Pig. 4.— A Moving Plant. Yolvox, one of the Green Algte. (After Oohn 

 X about 100, from Vines' " Student's Botany.") * 



the air-bubble and the Brownian movement, may be 

 puzzled by such forms as those we have already spoken 

 of — the motile spores of certain plants, or the motile 

 kinds of Green Algse. We have therefore figured 

 some of these fornis of vegetable life. The diSer- 

 ences would be more readily apparent if the diagrams 

 could be coloured. For the Algse contain the green 



