AMCEBA PROTEUS 7 



It is not easily made out under ordinary conditions, but 

 if the organism be killed and stained with iodine, the 

 nucleus is stained a deeper brown than the rest of the 

 protoplasm, and thus becomes easily apparent. Now 

 we must consider the nucleus with some degree of 

 reverential awe, for it is the vital centre, that structure 

 through which Life itself regulates the existence and 

 activities of a cell; it is the very heart of an organism, 

 and even more. When an Amoeba reaches its maximum 

 growth it divides into two, a process of reproduction 

 known as " fission." But in this division the nucleus 

 is always first divided; indeed, it regulates the division. 

 If an Amoeba be cut in two, and a part of the nucleus 

 be included in each half, then each half will develop 

 into a perfect individual; but if, in making the cut, the 

 nucleus is not divided, then the part containing it will 

 become a perfect individual, but the other part, although 

 it may live for a few days, and even send out pseudo- 

 podia, cannot creep, nor can it digest food, although it 

 may enclose it. 



What, then, are our conclusions in regard to Amoeba ? 

 In the first place it is a cell, or protoplast, without a 

 firm cell-wall. It can extemporize feet, and so move; 

 it can capture food and digest it in an extemporized 

 stomach ; it can reproduce its kind by the simple method 

 of fission; it is a speck of nucleated, living protoplasm 

 displaying animal characteristics; it feeds upon organic 

 food, such as microscopic plants; it cannot live in the 

 absence of such food; it is an animal, like all other 

 animals, utterly dependent, so far as food is concerned, 

 upon other organisms, for it cannot live on inorganic 

 substances. Before animals, no matter how small or 



