PROTOPLASM. THE INDIVIDUAL 39 



in the case of Hydra or Aphis, no such organism even when 

 producing sexual elements can be termed an Individual. 

 A seedling rosebush is a potential Individual, but a rose- 

 bush grown from a cutting can never be anything but a 

 part of an Individual. 



In the second place, if the complete cycle comprises the 

 Individual, one is not literally correct in applying the term 

 to any organism — or group of organisms — before it has 

 grown to its utmost limits and finished all its cell-cycles 

 to the extent permissible to the class of Individual in ques- 

 tion. A man can loosely be described as an Individual, 

 but he is only potentially one as long as he can produce 

 sexual elements and repair tissue loss. It is as indicating 

 all the content of the living growth-cycle that the term 

 " Individual " will be used in succeeding pages, and to 

 denote this it will always be written with a capital " I." 



It may well be questioned if there are such things as 

 " unicellular Individuals." Certainly, every unicellular 

 organism is not an Individual, nor is there necessarily 

 reproduction when a unicellular organism divides into two. 

 There is reason for the belief that all unicellular organisms, 

 whatever their kind and however marked their independence, 

 are but parts of or stages in the development of some 

 Discontinuously Multicellular Individual type. Our unit 

 growth-cycle is an act of atomic attraction followed by one 

 of repulsion, and our belief is that the repulsion manifested 

 in the division of a unicellular organism, itself an atomic 

 multiple, indicates that somewhere and sometime previously 

 an act of unicellular attraction, or " conjugation," must 

 have occurred. 



Our suggestion is, in fact, that the " unicellular Indi- 

 vidual " is fundamentally on a par with the intermediate 

 cell of the continuously multicellular organism, and that it 

 is the independence due to discontinuity which is misleading 

 and obscures the truth. 



On the other hand, the Individual composed of many 

 unicellular organisms is common in Nature, the cycle always 

 beginning with an act of attraction and the conjugation 

 of two of the organisms, and ending with their multiple 

 restoration or reproduction. And here one can but conclude 



