96 HOURS WITH NATURE. 



AMCEBA. 



They are mostly invisible to the naked eye, as they 

 rarely exceed one hundredth of an inch in diameter. 

 The most noticeable thing about an Amoeba is, that it is 

 never quite the same shape for long together. With 

 regard to this change of form, a distinguished Biologist 

 says that it takes place so slowly as to be almost imper- 

 ceptible, u like the movements of the hour-hand of a 

 watch, but by examining it at successive intervals, the 

 alteration becomes perfectly obvious, and at the end of 

 half an hour it probably has altered so much as to be 

 hardly like the same thing." Amcebas are composed 

 of a more or less jelly-like substance called "protop- 

 lasm," which is semifluid in character and is a very 

 complex chemical compound of Nitrogen, Carbon, Oxy- 

 gen, Hydrogen, and Sulphur &c. They are the simplest 

 forms of living things, each consisting of a single particle 

 of protoplasm which performs all the various functions by 

 which life is maintained. Dr. Hudson describes them as 

 " slow gliding lumps of jelly that thrust a shapeless hand 

 out where they will, and, grasping their prey with these 

 chance limbs, wrap themselves round their food to get 

 a meal ; for they creep without feet, seize without hands, 

 eat without mouths, and digest without stomachs." 



PROTOZOA. 



There are numerous other kinds of animals, or, more 

 correctly speaking, animalcules, consisting of single 

 particles of Protoplasm, which are all collectively called 



