LITOBIONTS 387 



Litobionts.l have ventured to suggest a general or inclusive 

 name, Litobionts, for the organisms which my observations lead me 

 to believe to exist, these very organisms of lower grade; (Xtros, 

 simple), simple-organisms. The Litobionts have distinctive char- 

 acters, such as small size, and simplicity of composition, but neverthe- 

 less, live, assimilate, grow, multiply; not only segmenting somewhat 

 after the manner of some higher, more or less filamentous organisms, 

 but multiplying by endogenous division, this latter being one of the 

 present observations, the endogenous process being exemplified in 

 the "granules" of the spermatidia of Spirina. (See p. 41.) 



Yet it is possible to over-emphasize the smallness of Litobionts. 

 It seems likely that we have been looking at Litobionts a long time, 

 Litobionts of the larger size, without recognizing their nature, just 

 as observers previous to the tune of Schleiden and Schwann had 

 been looking at cells without recognizing their nature. 



Just as the multicellular and unicellular organisms overlap each 

 other in the matter of size, so the unicellular organisms (having the 

 characteristic properties of cells as now defined) overlap the Lito- 

 bionts. There are unicellular organisms smaller than some Lito- 

 bionts. Or, in reverse, some Litobionts larger than some unicellular 

 organisms. 



That the Litobionts are much simpler than cells, is indicated by a 

 number of considerations. Their effects on light indicate that in 

 the main, they are composed of a smaller number of kinds of molecules 

 of a more orderly arrangement, what may perhaps be thought of 

 as forming a simpler plasm, Litoplasm. The fact that some of them 

 are soluble in certain chemical reagents (e.g., acetic acid), is another 

 indication of relative simplicity. In a word, we must conceive of 

 the Litobionts as made up of a smaller number of kinds of simpler 

 molecules manipulated through very much smaller distances, and 

 therefore necessarily (a matter of "economy," 'least resistance") by 

 simpler mechanism. It is quite conceivable that some Litobionts 

 may be smaller than some of the largest molecules. Not needing 

 these large and complex molecules, the mass of the Litobiont may 

 even be smaller than that of some such molecules. 



The duality characteristic of all matter must lead, however, to an 

 arrangement of the parts in Litobionts such that we can only think 

 of them at present largely in terms of what we know of cell physiology 

 and mechanics; simply because knowledge progresses exclusively 

 through the known to the unknown. Our knowledge of cells must be 

 one of the main sources of our Litobiont concepts. 



