60 VIGNETTED FROM INVISIBLE LIFE. 



all the lower forms of life, is performed in a regular 

 and methodical manner. In order clearly to under- 

 stand this process, another very simple yet impor- 

 tant part of the structure of the Amoeba must be 

 observed. This is seen in the sketch as a mere 

 dark spot. It is the nucleus. Within it, is also 

 seen another small dot named the nucleolus. These 

 are the germs of future generations. The power 

 and potentiality of life is stored carefully here ; 

 and consequently when a division is to take place a 

 portion of this important matter must go along with 

 each half. When fission is about to occur, a con- 

 striction, slight at first, is seen going on on each 

 side of the main body of the Amoeba, which gra- 

 dually increasing, at length embraces the nucleus ; 

 the nucleus then divides, giving half of its contents 

 to each part, and resuming in each its perfect form 

 and function. The appearance now presented is 

 that of two Amoebae, just linked together by an 

 ever-lessening tie ; and this finally parting asun- 

 der, the two forms pursue (each one for itself) its 

 own independent existence. This is the usual 

 method. Another has been observed when a 

 gelatinous cyst is formed, enclosing the whole 



