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Show 24 DROSERA ROTUNDIFOLIA. CHAP. II. The Inflection of the Exterior Ten~acles ~s directly caused by O~jects left in Contact w~th the~r 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 place.d on a single gland, the movement of the tentacle Is particularly well seen in .contrast with the statio~ary condition of the surrounding tentacles. (Seo 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 obsei:~ed with special care, distinctly, though slightly, changed its position in 10 s. (seconds); and this is the quickest movement seen by me. In 2m. 30 s. it had moved through an angle of about 45°. The move1nent as seen through a lens resembled that of the hand of a large clock. In 5 m. it had moved through 90°, and when I looked again aft r 10 m., the particle had reached the centre of the leaf; so that the whole movement was compl t d in less 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 stut·k 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, &o., cause inflection. M. Ziegler makes still more oxtmonlinary statements with ref:ip ct to the power of animal sub tanco' , which have boon l ft clo o to, but not in contact with, sulphate of quinine. The action of ·alts of quinine will be described in a future chapter. ince the app arauce of the paper above referred to, M. Zi gler has publi hod a book on tho same subject, entitled, 'Atonicite et Zoicite,' 1874. CHAP. II. INFLECTION INDIRECTLY CAUSED. 25 than 17 m. 30 s. In the course of some hours this . minute b~t of meat, from having been brought into contact w1th some of the glands of the central disc acted centrifugally on the outer tentarles, which all be~ came 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 35m. through an angle of 180° to the centre. The fragment on the fourth tentacle was very minute, and it was not carried to the centre until 3 hrs. had elapsed. In three other cas_es minute flies or portions of larger ones were earned to the centre in 1 hr. 30 s. In these seven cases, the fragments or small flies, which had been carried by a single tentacle to the central glands, were well embraced by the 9ther tentacles after an interval of from 4 to 10 hrs. I also placed in the manner just described six small balls of writing-paper (rolled up by the aid of pincers, so that they were not touched by my fingers) on the glands of six exterior tentacles on distinct leaves· three of these were carried to the centre in about 1 hr.: and the other three in rather more than 4 hrs.; but after 24 hrs. only two of the six balls were well embraced by the other tentacles. It is possible that the secretion may have dissolved a trace of glue or a~imalised matter from the balls of paper. Four particles of coal-cinder were then placed on the glands of four exterior tentacles; one of these reached the centre in 3 hrs. 40 m. ; the second in 9 hrs.; the third _within 24 hrs., but had moved only part of the way In 9 hrs.; whilst the fourth moved only a very short distanee in 24 hrs., and never moved any farther. Of the above three bits of cinder which were ultimately carried to the centre, one alone was well em braced by |