No. 627] 



ADAPTATION 



Here, likewise, we may legitimately speak of the need for 

 some sort of readjustment. Let us, then, restrict the 

 word to anything without which a species would become 

 extinct. 



With this limitation of meaning understood, let us re- 

 turn to certain questions which I have left unanswered. 

 Can we, on naturalistic grounds, conceive how an appro- 

 priate trend of variation could anticipate a given need; 

 or can we even conceive how it could be called forth by an 

 existing need? The former possibility certainly can not 

 be admitted without frankly taking refuge in principles 

 which lie beyond the range of scientific analysis. The 

 latter possibility has, however, been vaguely implied by 

 some writers on evolution. 



So far as the ''need" might be the result of some 

 marked change in the environment or in the functional 

 activities of the organism, it is credible that new varia- 

 tions might be offered to selection as a consequence of 

 disturbances in the germinal material. lUit liow could 

 these occur preponderatinylv m ilic (lii t ct ion of meeting 

 the particular need in question Oiili/ ni one iraij, so far 

 r/s / un, aurJ that uau hii tin /n, < mii^ arhiptnr 

 nn><h/n ninn/ <>l lln juiunf l>n<l »i \\n tlh' l.itt.-l may 

 <i.l.t].t itMll ( \t.« iinirnt.ilh. .u-(M.nhno to p, mciph . ai- 

 n-ady (riscnss..!. Tli." uvrin-.-olls could not ada].! them- 

 selves cxpri-iiiinitaliv, siiuT thr n.MMl is conini.iiilv one 

 which docs not as such aflcct thmi at all. rhu>. the 

 imperatix'c (Iniiaiul lor din t hil uvriuinal \anatioiis or 

 at least ones ot a usclul sort can he met, so tar as iiow 

 appears, only by assuming the transmission tt) the i;'erm- 

 cell of adaptive responses ot the jiarent hodv. 



The Lamarckian princi])le has tiie added adxantauc of 

 being able to account for many ol th«' •"luxui'ies" of 

 organization— adaptations, in the sense ot httmu- ilieir 

 possessors for a fullei- and more xaried lite, hut not of 

 any conceivable sur\i\al \alue. Onr own race, as has 

 often been f>ointed out. is endow imI with nmltitudes of 

 such faculties. V>\\\ w> an ^adU m lu . d m .Immi e\- 



