STMBIONTICISM 61 



"Symplasm" is a term proposed by Lohnis and Smith 

 for another phase of bacterial behavior. It represents a 

 stage in the various Ufe-cycles of bacteria. Briefly, it may 

 be described as a clumping together of a number of bacteria 

 of a single strain in which the boundaries of the individual 

 organisms are lost. The bacteria coalesce and resolve into 

 an amorphous mass; this constitutes the symplasm. Later, 

 in the completion of the Ufe cycle, individual bacteria are 

 reformed by a dissolution of the symplasm, Lohnis has 

 collected a considerable amount of evidence from the htera- 

 ture to support his own researches on this subject. Alm- 

 quist ('22), and others, also, have observed the symplasm 

 stage in the life cycles of certain bacteria. 



Cell fusion represents another type of expression of proto- 

 taxis. The end result in this type of activity may be repre- 

 sented by two kinds of cell relationships. In one case, cells 

 appear to ''flow together" and produce a true syncytium. 

 The author observed a type of fusion in the branchial epi- 

 thelium of the lamprey larva in which the cell boundaries 

 completely disappeared (WalUn, '18). The other type of 

 cell relationship is found in certain tissues in which the 

 cells have protoplasmic bridges extending from one to 

 another. 



The interesting experiments of Galtsoff ('25) on "Re- 

 generation after dissociation" of the cells of the sponge, 

 in which "the regeneration is primarily the process of 

 coming together of cells, accompanied by their further 

 differentiation," demonstrates another phase of the same 

 principle. 



In symbiosis two dissimilar organisms become intimately 

 associated. This type of vital relationship was, apparently, 

 first observed by Reinke in 1872, who named the phe- 

 nomenon "consortism." In 1879, De Bary observed and 

 recorded the same phenomenon, and introduced the term 

 "symbiosis," which has since been adopted into common 

 usage. 



