OF VERY MINUTE AMCEB^E. 2O3 



name, because it is manifested by every form of living 

 matter, though not to be observed in all cases with facility. 

 I have, therefore, termed these movements vital movements* 

 I have been able to watch the movements of small 

 amoebae, which multiplied freely without first reaching the 

 size of the ordinary individuals, and have represented the 

 appearances I observed under a magnifying power of 5,000 

 diameters, in the case of some of the most minute amcebse 

 I have been able to discover. (PI. Ill, fig. 3.) Several 

 of these were less than iWoo t.h of an inch in diameter, 

 and yet were in a state of most active movement. The 

 alteration in form was very rapid, and the different tints in 

 the different parts of the moving mass, resulting from 

 alterations in thickness, were most distinctly observed. 

 The living bodies might, in fact, be described as consisting 

 of minute portions of very transparent material, which, 

 manifested very active movements in various directions, in 

 every part, and was capable of absorbing nutrient materials 

 from the surrounding medium. A portion which was at 

 at one moment at the lowest point of the mass might in an 

 instant pass to the highest part. In these movements one 

 part seemed, as it were, to pass through other parts, while 

 the whole mass moved now in one, now in another direction 

 and movements in different parts of the mass occurred in 

 directions different from that in which the whole was 

 moving. What movements in lifeless matter can be com- 

 pared with these ? 



* This movement of simple living matter is very different from the 

 so-called spontaneous movements of the higher animals which are brought 

 about by the action of a highly complex nervo-muscular apparatus, not 

 a vestige of which exists in living matter. 



