64 



SCIENCE. 



[N. S. Vol. XIV. No. 341. 



Thus two molecules of acetic acid supplied 

 with the proper food (phosphorus pentachloride 

 zinc ethyl and oxygen) have been able to assim- 

 ilate additional atoms of CH.O, the result being 

 the formation o? four molecules of acetic acid 

 (growth), together with certain excreta (phos- 

 phorus pentachloride, hydrochloric acid and 

 zinc chloride). Arguing for this case, Professor 

 Giglio-Tos lays down the following conditions 

 as necessary in order that a molecule may ex- 

 hibit the phenomena of assimilation : 



1. It must be able, with the aid of assimila- 

 tion, to divide into molecules similar to itself. 



2. The necessary nutritive substance must be 

 always present. 



3. The nutritive and secondary (excreta) 

 products must not act destructively upon each 

 other. 



4. The various processes of assimilation must 

 follow one another in a definite order. 



5. The physical conditions (heat, light, etc.) 

 must be suitable. 



The molecules of protoplasm, which are 

 termed biomolecules, possess or exist under these 

 necessary conditions and hence exhibit assimila- 

 tion. 



Having established this point, the author then 

 proceeds to discuss differentiation. If we repre- 

 sent the primary molecule by a and the various 

 compounds formed during the assimilative 

 process by b, c, cl, and M, the process indicated 

 above may be graphically composed as 



a h ■■ c -d ■■■ M=a-\- a 

 It is not necessary, however, that the resulting 

 molecules should be identical in composition 

 with that from which they arose, and the series 

 may run thus : 



„/ ... 6/...c^... (Z/... ii// = e'4-e/ 



and finally it is possible that? the two resulting 

 molecules may differ from one another, thus 

 «// ... y/ ... c^-' - d'^ ■■■ if-' == e'^ + {/'' 

 As a combination of these various results of 

 assimilation, which the author terms respect- 

 ively autogenetic, homogenetic and hetero- 

 genetic, the differentiation of the biomolecules 

 is produced. The biomolecules represent for 

 Professor Giglio-Tos the fundamental con- 

 stituents of protoplasm, but they are chemical* 

 constituents, and like many of his predecessors 



he finds it necessary to postulate the existence 

 of living particles composed of an aggregation 

 of biomolecules and which he terms hiomores. 

 These he likens to a double salt and, since each 

 biomore is composed of living molecules, it too 

 is a living compound, and from the biological 

 standpoint may be regarded as a symbiosis of 

 molecules, since for the preservation of the 

 biomore the component biomolecules must react 

 favord,bly upon one another. The biomores 

 are aggregated symbiotically to form a hioplasma 

 and a symbiotic system of biomores which per- 

 forms all the functions of life and constitutes a 

 living unit, is termed a hiomonad, while, finally, 

 a cell is a biomonad ' characterized by the chemi- 

 cal nature of certain biomores which form its 

 nucleus ' or in other words is a differentiated 

 biomonad. 



Such in brief is the fundamental idea 

 which the author expounds in the first five 

 chapters of his book, and in the succeeding 

 pages he proceeds to discuss the phenomena of 

 cell division in the light of this idea. Eepro- 

 duction is after all merely discontinuous growth 

 and the causes which determine the growth or 

 division of a molecule will be the same in the 

 case of a biomore, or biomonad, or a cell. The 

 division of a molecule depends upon the orienta- 

 tion of its constituent molecules, and the divi- 

 sion of a biomonad, accordingly, is due to the 

 orientation of its constituent biomores. It 

 would lead us too far to attempt to follow the 

 author in his minute analysis of the phenomena 

 of karyokinesis, and it must suffice to quote 

 from the concluding paragraphs of the book : 

 " The property of division, which chai'acterizes 

 living substances, is not due to a special force. 

 It is only the necessary, inevitable consequence 

 of the constitution of this substance and of 

 assimilation." "The force which unites the 

 particles of living matter is the same as that 

 which unites the parricles of dead matter and 

 is sufficient for the ex|ilanation of the phenom- 

 ena of division. Division always occurs under 

 the action of this force, whatever may be the 

 constitution of the living substance, and the 

 various figures w'hich appear during division 

 and which characterize cytodieresis are only 

 the morphological consequences of that consti- 

 tution." 



