were then placed (every instrument with which they were touched having been previously immersed in boiling water) on the glands of several leaves, and they acted in exactly the same manner as other particles, which had been purposely handled for some time.  Bits of a boiled egg, cut with a knife which had been washed in boiling water, also acted like any other animal substance.  I breathed on some leaves for above a minute, and repeated the act two or three times, with my mouth close to [[page 24]] them, but this produced no effect.  I may here add, as showing that the leaves are not acted on by the odour of nitrogenous substances, that pieces of raw meat stuck on needles were fixed as close as possible, without actual contact, to several leaves, but produced no effect whatever.  On the other hand, as we shall hereafter see, the vapours of certain volatile substances and fluids, such as of carbonate of ammonia, chloroform, certain essential oils, &c., cause inflection.  M. Ziegler makes still more extraordinary statements with respect to the power of animal substances, which have been left close to, but not in contact with, sulphate of quinine.  The action of salts of quinine will be described in a future chapter.  Since the appearance of the paper above referred to, M. Ziegler has published a book on the same subject, entitled ‘Atonicit et Zoicit,’ 1874.) [page 24]

The Inflection of the Exterior Tentacles as directly caused by Objects left in Contact with their Glands.

I made a vast number of trials by placing, by means of a fine needle moistened with distilled water, and with the aid of a lens, particles of various substances on the viscid secretion surrounding the glands of the outer tentacles.  I experimented on both the oval and long-headed glands.  When a particle is thus placed on a single gland, the movement of the tentacle is particularly well seen in contrast with the stationary condition of the surrounding tentacles. (See previous fig. 6.) In four cases small particles of raw meat caused the tentacles to be greatly inflected in between 5 and 6 m.  Another tentacle similarly treated, and observed with special care, distinctly, though slightly, changed its position in 10 s. (seconds); and this is the quickest movement seen by me.  In 2 m. 30 s. it had moved through an angle of about 45o.  The movement as seen through a lens resembled that of the hand of a large clock.  In 5 m. it had moved through 90o, and when I looked again after 10 m., the particle had reached the centre of the leaf; so that the whole movement was completed in less [page 25] than 17 m. 30 s.  In the course of some hours this minute bit of meat, from having been brought into contact with some of the glands of the central disc, acted centrifugally on the outer tentacles, which all became closely inflected.  Fragments of flies were placed on the glands of four of the outer tentacles, extended in the same plane with that of the blade, and three of these fragments were carried in 35 m.