CHAP.. VI. DIGESTION. 93 



additional day the angles of the cubes were dissolved and 

 rounded ;* but the cubes were too large, so that the leaves 

 were injured, and after seven days one died and the others 

 were dying. Albumen which has been kept for four or five 

 days, and which, it may be presumed, has begun to decay 

 slightly, seems to act more quickly than freshly boiled eggs. 

 As the latter were generally used, I often moistened them 

 with a little saliva, to make the tentacles close more 

 quickly. 



Experiment 2. A cube of -^ of an inch (i.e. with each side 

 T a o of an inch, or 2'54 mm., in length) was placed on a leaf, and 

 after 50 hrs. it was converted into a sphere about -^ of an inch 

 (1'905 mm.) in diameter, surrounded by perfectly transparent 

 fluid. After ten days the leaf re-expanded, but there was still 

 left on the disc a minute bit of albumen now rendered trans- 

 parent. More albumen had been given to this leaf than could 

 be dissolved or digested. 



Experiment 3. Two cubes of albumen of -^ of an inch 

 (T27 mm.) were placed on two leaves. After 46 hrs. every 

 atom of one was dissolved, and most of the liquefied matter 

 was absorbed, the fluid which remained being in this, as in all 

 other cases, very acid and viscid. The other cube was acted 

 on at a rather slower rate. 



Experiment 4. Two cubes of albumen of the same size as 

 the last were placed on two leaves, and were converted in 

 50 hrs. into two large drops of transparent fluid ; but when 

 these were removed from beneath the inflected tentacles, and 

 viewed by reflected light under the microscope, fine streaks of 

 white opaque matter could be seen in the one, and traces of 

 similar streaks in the other. The drops were replaced on the 

 leaves, which re-expanded after 10 days; and now nothing 

 was left except a very little transparent acid fluid. 



Experiment 5. This experiment was slightly varied, so that 

 the albumen might be more quickly exposed to the action of the 

 secretion. Two cubes, each of about ^ of an inch ( 635 mm.), 

 were placed on the same leaf, and two similar cubes on another 



* In all my numerous experi- teristic of the digestion of albu- 



ments on the digestion of cubes men by the gastric juice of ani- 



of albumen, the angles and edges mals. On the other hand, he 



were invariably first rounded. remarks, "les dissolutions, en 



Now, Schiff states ( ' Lemons chimie, ont lieu sur toute la sur- 



phys. de la Digestion,' vol. ii. face des corps en contact aveo 



1867, p. 149) that this is charac- 1'agent dissolvant." 



