ON THE POWER OF MOVEMENT IN PLANTS. 147 



has shifted its position. It has a singular tendency before its 

 period of fructification ensues, to cUmb up any erect object 

 like a tree, or stump, and here it may be found at rest forming its 

 capsule containing spores which by-and-bye are set free as naked 

 masses of protoplasm ; these myxamcehce^ as they are called, 

 coalesce later on, three or four of them or more making a 

 Plasmodium such as we started with ; they are also endowed with 

 power of motion, using this power in order to coalesce. The 

 Plasmodium of Didymium will travel as fast as ten millimetres in a 

 minute. 



A similar power is seen in the protoplasmic filaments ejected 

 from the glandular hairs on the leaves of the Common Teasel, 

 where Mr, F. Darwin has proved their power of absorbing nutri- 

 ment from the bodies of insects drowned in water contained in 

 the cups formed by the connate leaves. It is seen also in the 

 cups of the leaves of the celebrated Compass plant of the prairies. 

 Here the power of movement, as in our first case (cell-contents), has 

 to do with the protoplasm, and is quite independent of any 

 external agent. 



C. — Motion of Embryonic Cells, or ' Zoospores,' 



AND OF ' AnTHEROZOIDS.' 



This is accomplished by means of vibratile cilia with which the 

 organisms are provided. These forms are seen in two chief varieties : 



I. — The Zoospores or Swarmspores of certain Algce^ for instance, 

 Froiococcus, the Red Snow Vl^nt, y^dogofiiutn, Vaucheria, etc., and 

 of some Fu?igi, such as Peronospora infestafts, the Potato fungus ; 

 they consist of embryonic cells set free by rupture of the parent- 

 cell, and are naked masses of protoplasm provided with these 

 cilia, but destitute of any cell-wall during their motile period ; they 

 move with astonishing rapidity, sometimes rotating on their own 

 axis, sometimes with a comical rolling motion, lashing the water 

 with one cilium, while the other trails behind, sometimes fixing 

 themselves by one cilium and spinning round on it by means of the 

 other ; after a time, they lose their cifia, develop a cellulose coat, 

 become respectable members of society, and having " sown their 

 wild oats," gradually grow up to adult forms. 



II. — The Atitherozoids or male elements of reproduction formed 



