THE MOVEMENTS AND HABITS OF PLANTS. 33 



the adjoining and inflected tentacles on the same leaf was 

 decidedly acid. "With leaves excited by particles of glass 

 placed on the central glands, the secretion which collects 

 on the disk beneath them was much more strongly acid 

 than that poured forth from the exterior tentacles, which 

 were as yet only moderately inflected. "When bits of al- 

 bumen (and this is naturally alkaline) or bits of meat 

 were placed on the disk, the secretion collected beneath 

 them was likewise strongly acid. As raw meat moistened 

 with water is slightly acid, I compared its action on lit- 

 mus-paper before it was placed on the leaves, and after- 

 ward when bathed in the secretion ; and there could not 

 be the least doubt that the latter was very much more 

 acid. I have indeed tried hundreds of times the state of 

 the secretion on the disks of leaves which were inflected 

 over various objects, and never failed to find it acid. "We 

 may, therefore, conclude that the secretion from unex- 

 cited leaves, though extremely viscid, is not acid or 

 only slightly so, but that it becomes acid, or much more 

 strongly so, after the tentacles have begun to bend over 

 any inorganic or organic object ; and still more strongly 

 acid after the tentacles have remained for some time 

 closely clasped over any object. 



I may here remind the reader that the secretion ap- 

 pears to be to a certain extent antiseptic, as it checks the 

 appearance of mold and infusoria, thus preventing for a 

 time the discoloration and decay of such substances as the 

 white of an egg, cheese, etc. It therefore acts like the 

 gastric juice of the higher animals, which is known to 

 arrest putrefaction by destroying the microzymes. 



_ „„ Cubes of about one twentieth of an inch 



° ' (1 '27 millimetre) of moderately roasted meat 

 were placed on five leaves, which became in twelve hours 

 3 



