2 CHEMISTRY OF THE PROTEIDS 



compounds, which cannot react chemically with the mother-substances 

 from which they are derived, but which by interacting with new 

 radicals give rise to a cycle of events. In the following diagram the 

 author has endeavoured to make his meaning clear. From the nucleus 

 two arrows pass outwards : the one on the right represents the forma- 

 tion of ' extra-cellular ' zymogen granules, their disruptive enzymes 

 having the function of acting on extraneous chemical compounds in 

 such a .waj^ as^to -make them available to the cell individual. These 

 '$u'zymesvca^gej,fbr example, albumin into albumoses, peptones and 

 aniinq-acids. The ai*row on the left of the figure represents 'intra- 

 callu'lar' 'zymo'genSj'olie function of which is a constructive one; they 

 bring about an aggregation of those amino-acids and peptone-like 

 bodies which have been liberated from proteid food by the extra- 

 cellular enzymes. The aggregates so formed constitute the main bulk 

 of the cell-plasm, and they are subsequently transformed by the 

 activity of the nucleus 1 into the extra-cellular and intra-cellular 

 zymogens already alluded to. The cycle of events just described is 

 what we call life. Cessation of life, or death, will be produced either 

 by the inability to procure food, which is necessary to counterbalance 

 the wear and tear necessitate'd by the conversion of one chemical com- 

 pound into another this amounts to death by starvation, or secondly, 

 by the inability of the nucleus to digest the food and so make it avail- 

 able to the individual cell, as seen in old age. In addition to these 

 two kinds of physiological death, we have another form due to 

 violence, as, for example, by the application of excessive heat or cold 

 or inorganic (corrosive sublimate, etc.) or organic (bacteria) poisons. 



Those who take an interest in the actual phenomena exhibited by 

 cells fed on proteids and derivatives of proteids, and who wish to see 

 the histological appearances which cells assume during the various 

 stages in a ' life-cycle ' will find a detailed account in the papers of 

 Lily Huie. 2 This work, done under the author's care, is now being 

 continued by the author, for there is no other way of gaining an in- 

 sight into the working of the different organs of a cell. It is only by 

 histological research based on a sound knowledge of chemistry and 

 physics that we will be able to understand and to modify the events 

 in the life-cycle, that we will be able to accelerate and to slow down 

 nuclear and cytoplasmic activities. The importance of such research 

 in connection with cancer and all fevers cannot be overestimated. 



1 Gustav Mann : ' What is Life ? ' Trans, of the Oxford University Junior Scientif. 

 Club. Feb. 1899. Read Nov. 1898. 



2 Lily Huie, Quarterly Journ. of Micr. Science, 39. 387 (1896-97), and ibid. 42. 203 

 (1899). 



