132 DKOSERA KOTUNDIFOLIA. CHAP. VL 



rates and in very different degrees ; and the ten- 

 tacles remain inflected for very different periods of 

 time. Quick inflection depends partly on the quan- 

 tity of the substance given, so that many glands are 

 simultaneously affected, partly on the facility with 

 which it is penetrated and liquefied by the secretion, 

 partly on its nature, but chiefly on the presence of 

 exciting matter already in solution. Thus saliva, or 

 a weak solution of raw meat, acts much more quickly 

 than even a strong solution of gelatine. So again 

 leaves which have re-expanded, after absorbing drops 

 of a solution of pure gelatine or isinglass (the latter 

 being the more powerful of the two), if given bits 

 of meat, are inflected much more energetically and 

 quickly than they were before, notwithstanding that 

 some rest is generally requisite between two acts 

 of inflection. We probably see the influence of tex- 

 ture in gelatine and globulin when softened by 

 having been soaked in water acting more quickly 

 than when merely wetted. It may be partly due to 

 changed texture, and partly to changed chemical 

 nature, that albumen, which has been kept for some 

 time, and gluten which has been subjected to weak 

 hydrochloric acid, act more quickly than these sub- 

 stances in their fresh state. 



The length of time during which the tentacles re- 

 main inflected largely depends on the quantity of the 

 substance given, partly on the facility with which it is 

 penetrated or acted on by the secretion, and partly 

 on its essential nature. The tentacles always remain 

 inflected much longer over large bits or large drops 

 than over small bits or drops. Texture probably 

 plays a part in determining the extraordinary length 

 of time during which the tentacles remain inflected 



