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Show 50 DROSERA ROTUNDIFOlJIA. CHAr'. III. lowed from an r.m mer.s w. n of from 5 m. to 10 rr1. in an equally 1 t . f the carbonate. . strong sou wn ° 1 ced in thirty minims of a solutiOn of J..Jastly, a leaf ~as P ~ ammonia to 43,750 of water (1 gr. to one part of phos:p ...l ate? d 1_ of a grain (' 04079 mgr.); this 100 oz. ) ' so that rt recerve Tioo . fl t d . d ft . d the tentac 1e s t o be strongly rn eo e , a· n a er soon cause of the cells were aggregated rnto oval. 24 hrs. the contents ses with a conspicuous current of and irregularly ~lo~u~a~n~a~he' walls. But after so long an protoplasm flowl~g ro ld have ensued, whatever had caused interval aggregatwn won inflection. lt b sides those of ammonia, were tried Only ~few other sa s, e a re ation. A leaf was placed in in rela~IOn to the pr~ce~s ~~:ri~e ~f sodium to 218 of water, and a solutwn of one part~ o~ the cells were aggregated iuto small, after 1 hr. the conten . h ma~ses . these after 2 hrs. wr,re irregular.!~ globula~, b~w~\~y It w~s evident that the protoalmost drsmtegr~te. ~n f affe~ted. and soon afterwards some plasm had been rnJurwus .Y t ' These effects differ aJto-of the cells appeared Jurted e~: fhe several salts of ammonia, gether from thos.e pro uce. fluids and by inorganic particles as well as by vanous organ~~tion of' the same strength of carplaced onf th; gla~d:~rr!n:~e of potash acted in nearly the same bonate o so a an .· . ain after 2 hrs. 30 m., the manner ~f th~ chlo~l~~' t~~d :r:~~:ghad' emptied themselv.es of ~~::: ~~0~~ ;~~y contents. We shall see in the mghth chapter that solutions of several salts ~f .soda of half the ~ov~ strength cause inflection, but do not. lnJ~re the leav~s. . ~ao~· solutions of sulphate of quinine, of niCotine, campl~or , po;so the cobra, &c., soon induce well-marked aggreg~twn ; w lerea) certain other substances (for i~stance, a solutiOn of curare have no such tendency. . d tl o·h Many acids, though much diluted, are pOisonous ; an 10~o ~ as will be shown in the eighth chapter, the_Y cause the ens tacles to bend, they do not excite true ag?regatr~n. ~d1~8 ~~7v~f were placed in a solution of one part of benzoiC aCI o l t . d . 15m the purple fluid within the cells had shrun c wa er, an rn · . · d ft · 1 hr a little from the walls, yet when carefully examrne a ei 1 f 20m there was no true aggregation; and after 24 hTs. t 1e e~ was ~vidently dead. Other leaves in iodic acid, diluted .to 1~ e same degree showed after 2 h rs. 15 m. the same shd rutln e\.seen appearance ~f the purple fluid within ~he cells ;. an be ~lled after 6 hrs. 15 m., were seen under a h1gh po~er to lasm with excessively minute spheres of dull reddiSh protop ' CHAP. III. THE PROCESS OF AGGREGATION. 51 which by the next morning, after 24 hrs., had almost disappeared, the leaf being evidently dead. Nor was there any true aggregation in leaves immersed in propionic acid of the same strength; but in this case the protoplasm was collected in irregular masses towards the bases of the lower cells of the tentacles. A filtered infusion of raw meat induces strong aggregation, but not very quickly. In one leaf thus immersed there was a little aggregation after 1 hr. 20 m., and in another after 1 hr. 50 m. With other leaves a considerably longer time was required: for instance, one immersed for 5 hrs. showed no aggregation, but was plainly acted on in 5 m., when placed in a few drops of a solution of one part of carbonate of ammonia to 146 of water. Some leaves were left in the infusion for 24 hrs., and these became aggregated to a wonderful degree, so that the inflected tentacles presented to the naked eye a plainly mottled appearance. The little masses of purple protoplasm were generally oval or beaded, and not nearly so often sphe1·ical as in the case of leaves subjected to carbonate of ammonia. They underwent incessant changes of form ; and th9 current of colourless protoplasm round the walls was conspicuously plain after an immersion of 25 hrs. Raw meat is too powerful a stimulant, and even smaJl bits generally injure, and sometimes kill, the leaves to which they are given: the aggregated masses of protoplasm become dingy or almost colourless, and present an unusual granular appearance, as is likewise the case with leaves which have been immersed in a very strong solution of carbonate of ammonia. A leaf placed in milk had the contents of its cells somewhat aggregated in 1 hr. Two other leaves, one immersed in human saliva for 2 hrs. 30 m., and another in unboiled white of egg for 1 hr. 30m., were not acted on in this manner; though they undoubtedly would have been so, had more time been allowed. These same two leaves, on being afterwards placed in a solution of carbonate of ammonia (3 grs. to 1 oz.), had their cells aggregated, the one in 10m. and the other in 5 m. Several leaves were left for 4 hrs. 30m. in a solution of one part of white sugar to 146 of water, and no aggregation ensued; on being placed in a solution of this same strength of carbonate of ammonia, they were acted on in 5 m. ; as was likewise a leaf which had been left for 1 hr. 45 m. in a moderately thick solution of gum arabic. Several other leaves were immersed for some hours in denser solutions of sugar, gum, and starch, anrl they had the contents of their cells greatly aggregated. Thir:: E 2 |
