622 THEORY OF INJURY AND RECOVERY. HI 



duction of any new reactions. All that we need to postulate is that 

 during development the relative rates of the reactions change. The 

 processes involved in irritability, as well as those concerned in injury 

 and death, may be accounted for in this way. We thus arrive 

 at a very simple conception of the underlying mechanism of Hfe 

 processes, which may be useful in formulating a theory of living 

 matter. 



As an illustration of the effect of changes in relative rates we may 

 take the substance, M, in the series 



It is evident that we may increase the value of if in a variety of 

 ways, as by increasing the rate of 0—^S, S—^A, A-^M, or of any two 

 of these reactions, or of aU of them simultaneously. We may decrease 

 the amount of M by decreasing the rates of these reactions or by 

 increasing the rate of M—^B (or increase M by decreasing this rate). 

 We may likewise increase (or decrease) M by increasing (or decreas- 

 ing) the amount of 0. Furthermore if side reactions occur, such as 

 N—^O^P or R-^S—>T their rates will also affect the amount of M. 

 It must also be remembered that any one of the substances in the 

 system might act as an accelerator or inhibitor of any of the reactions. 

 With such a system a great variety of processes is possible. 



It is possible that such systems may play an important role in the 

 fundamental processes of living matter. 



SUMMARY. 



Tissues of Laminaria transferred from sea water to solutions of 

 pure salts, and thence to other solutions of pure salts, or to sea water, 

 behave in a manner which can be predicted by means of the equa- 

 tions previously developed. 



The behavior of the tissue may be explained as due to a series of 

 catenary reactions. It is possible that a similar explanation may be 

 applied to other fundamental life processes. 



