REJUVENESCENCE AND DEATH 299 



In certain bacterial diseases, such for example as typhoid fever, 

 a very great decrease in body-weight may occur, and it is often 

 observed that the body-weight becomes greater and the person 

 apparently more vigorous after recovery than before the illness. 



These various facts viewed in the light of the effects of starva- 

 tion and reduction in the lower invertebrates indicate that, even in 

 man, reduction by starvation or other means may bring about some 

 degree of rejuvenescence through the breakdown and elimination 

 of constituents of the cellular substratum. During reduction in 

 these cases the rejuvenescence is potential rather than actual, and 

 it becomes apparent only when recovery occurs. But rejuvenes- 

 cence by reduction is Jimited in the higher animals, for reduction 

 in these forms soon ends in death, so that there is at present no 

 immediate prospect of our being able to rejuvenate ourselves to 

 any great degree, or to retard senescence or delay death to any 

 great extent by any such means. Under certain conditions long- 

 continued or periodic starvation may bring about an appreciable 

 rejuvenescence, but it is not in any sense a cure-all for human ills. 

 There is not the slightest doubt that certain recent books and 

 articles on the therapeutic value of starvation, written by laymen 

 who have experimented on themselves, have done great harm to 

 many persons. Certainly no one who desires to subject himself to 

 experiment of this kind should do so without submitting first to a 

 thorough medical examination and to medical observation and 

 control during the experiment. Where weakness or organic disease 

 exists, such experiments may be only a means of aggravation and 

 so hasten, rather than delay, death. And even if such diseases as 

 typhoid fever do in some cases accomplish a slight degree of rejuve- 

 nescence, no one will be inclined to regard them as an unmixed good. 

 In too many cases they serve only to develop or aggravate 

 weaknesses or to prepare the way for other infections, and so to 

 shorten life rather than to prolong it. 



A recent study of the susceptibility to the cyanides and to lack 

 of oxygen of fishes during starvation, by Mr. M. M. Wells,^ seems 

 to indicate that, as regards the effect of starvation, the fishes 



' Mr. Wells, formerly an assistant in the Department of Zoology of the University 

 of Chicago, has not yet completed his investigations, but very kindly permits the 

 citation of certain of the results obtained. 



