400 Mr. William Bate Hardy [April G, 



right down on to its foot ; if tliat does not get rid of the irritant, it 

 looses its hold and swims away. 



These responses ha^'e been analysed with great care in order to 

 elucidate the nnderlying mechanism. I can stop only to point out 

 the element of purpose. In order to get rid of an irritation, a certain 

 moyement is tried ; it fails, another moyement is tried ; it fails, and 

 a third moyement is tried. 



Now, it must be clearly understood that organisation will account 

 for these phenomena. Quite as remarkable a series of responses, each 

 in turn designed to get rid of an irritant, can be obtained from a frog 

 which has been depriyed of its brain, and therefore presumably lacks 

 both consciousness and intelligence. And step by step, as organisa- 

 tion adyances, the response gains in complexity, until the human 

 imagination is unable to unrayel the chain of cause and effect. But 

 the biologist is cognisant of no break in the series from the choice of 

 a yibrio, which can be analysed algebraically, to the choice of a 

 child between two toys. 



The faculty, clearly seen in the case of Stentor, of storing im- 

 pressions, so that the response to any particular stimulus is in part 

 conditioned by the stimuli which haye preceded it, is h familiar pro- 

 perty of living matter, and also of matter in the colloidal state. 

 The molecular state of a jelly is not fixed by the conditions of the 

 moment. Just as a piece of wrought iron has properties different 

 from those of cast iron, so the circumstances which attend the 

 making of a jelly — temperature, concentration, and the like — confer 

 on it an internal structure which controls its ])roperties for years to 

 come. liach jelly, therefore, has an indiyiduality due to the record 

 which it bears of its past. 



Take another case. A vertical rod of Ayax is bent, first north, 

 then south, then east, then west, and so on. Left to itself, it will 

 quietly work out these movements in the reverse order. It bends 

 first west, then east, tlien south, then north, and so on. The molecular 

 structure of the wax is such as to preser^'e a record not only of the 

 fact that it has been moved, but also of the number, direction, and 

 order of the several movements. 



The Faculty of Growth. 



If it ])e true, as some chemists think, that in the process of oxida- 

 tion there are always two ))r{)cesses more or less concurrent— the first 

 one of synthesis, in'which bodies of increased chemical com] )lexity are 

 formed by tlie union of the oxygen and the combustible sul)stance ; 

 the second one of analysis, which su])ervenes only wlien tlie synthetic 

 ])r()ducts reach a degree of com])]exity where they are unstal)le at the 

 particular tem])ei'ature and ])ressure— then, considei-ed in a general 

 way, the processes of assimilation and growth of living matter are 

 exceptional only in the pioniini-ncc and permanence of the synthetic 



