132 DROSERA ROTUNDIFOLIA. Crar. VI, 
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 
