OLD AGE.« 



By EiviE Metchnikoff, 



Suhdircctor of the I'listeiir InstHulc. 



Ill eoiiiplianee ^Yit]l tlie request of Doctor Toulouse, editor of tlie 

 Revue Scientifique, I will try to give you an idea of the present 

 state of our knowledge concerning old age, and I shall begin hy 

 speaking- of the difficulty of the task which I have to perform. The 

 l^rohleni of old age is one of the most comi^licated and difficult found 

 in the biological field. As it is far from being solved it Avill be 

 impossible for me to present to 3'ou a completed study with results 

 sufficiently precise to be practically a]:)plied. On the other iiarul, 

 the course of procedure which we pursue in studying this question 

 has already been made public, and consequently contains nothing 

 especialh' new. 



The reason why, in spite of these disadvantages, T have accepted 

 the ])r()position of M. Toulouse is because I wish to inform tin' j)ub- 

 lic concerning the extent of our investigations upon old age and to 

 make known what an inmiense field yet remains to l>e covered before 

 we can arrive at a satisfactory solution of tlie i)roblem. 



In considering this question of old age we are beset on every side 

 with difficulties. At what period of our life does this ultimate 

 stadium l)egin; at what time ought a man to sa}' that, having entered 

 upon this stage of his existence he dare no longer conduct himself 

 as an able-bodied individual? You will doubtless recall that it was 

 but a few months ago that the students of the faculty of medicine 

 in Paris loudly and noisily j^rotested against the decision of the 

 Senate that had suspended the law prescribing a limit of age for the 

 professors. " We do not want old dotards," declared these young 

 men. It is not rare to see old scientists of very great merit remain in 

 their chairs up to an age when they are no longer capal)le of assim- 

 ilating scientific progress, of judging correctly concerning ne^v ad- 

 vances. Their auditors readily see that they are no longer abreast 



«A lecture given in the Salle des Agi-ieiiltcurs, vw d'Atliriics, .Tiily S, 1904. 

 Trausliitcd, by perinisslon, from the Revue SeleutUiquc (I'aris), r.tli series, Vol. 

 II, pp. (;.")-7o Mild J»T-i(»r). 



533 



