166 DROSERA ROTUNDIPOLIA. [Chap. IX 



touched the Bolution, as Bhown by their blackness; but hardly any 

 motor influence was transmitted to the outer tentacles. After 22 

 hrs. most of the glands on the discs npi)eared dead; but this could 

 not have been the case, as, wlien bits of meat were placed on three 

 of them, some few of the outer tentacles were inflected in 24 hrs. 

 Hence nicotine has a great tendency to blacken the glands and to 

 induce aggregation of the protoplasm, but, except when pure, has 

 very moderate power of inducing inflection, and still less power of 

 causing a motor influence to be transmitted from the discal glands 

 to the outer tentacles. It is moderately poisonous. 



Atropine. A grain was added to 437 grains of water, but waa 

 not all dissolved ; another grain was added to 437 grains of a mix- 

 ture of one part of alcohol to seven parts of water; and a third 

 solution was made by adding one part of valerianate of atropine to 

 437 of water. Half-minims of these three solutions were placed, in each 

 case, on the discs of six leaves; but no effect whatever was pro- 

 duced, excepting that the glands on the discs to which the valeri- 

 anate was given were slightly discoloured. The six leaves on 

 which drops of the solution of atropine in diluted alcohol had 

 been left for 21 hrs. were given bits of meat, and all became in 

 24 hrs. fairly well inflected; so that atropine does not excite 

 movement, and is not poisonous. I also tried in the same man- 

 ner the alkaloid sold as daturine, which is believed not to differ 

 from atropine, and it produced no effect. Three of the leaves on 

 which drops of this latter solution had been left for 24 hrs. were 

 likewise given bits of meat, and they had in the course of 24 hrs. 

 a good many of their submarginal tentacles inflected. 



Veratrine, Colchicine, Thcine. Solutions were made of these 

 three alkaloids by adding one part to 437 of water. Half-minims 

 were placed, in each case, on the discs of at least six leaves, but no 

 inflection was caused, except perhaps a very slight amount by the 

 theine. Half-minims of a strong infusion of tea likewise produced, 

 as formerly stated, no effect. I also tried similar drops of an in- 

 fusion of one part of the extract of colchicum, sold by druggists, to 

 218 of water; and the leaves were observed for 48 hrs., without any 

 effect being produced. The seven leaves on which drops of vera- 

 trine had been left for 26 hrs. were given bits of meat, and after 

 21 hrs. were well inflected. These three alkaloids are therefore 

 quite innocuous. 



Curare. One part of this famous poison was added to 218 of 

 water, and three leaves were immersed in ninety minims of the 

 filtered solution. In 3 hrs. 30 m. some of the tentacles were a little 

 inflecte<l; as was the blade of one, after 4 hrs. After 7 hrs. the 

 glands were wonderfully blackened, showing that matter of some 

 kind had been absorbed. In hrs. two of the loaves had most 

 of their tentacles sub-inflected, but the inflection did not increase 

 in the course of 24 hrs. One of these leaves, after being immersed 

 for 9 hrs. in the solution, was placed in water, and by next 

 morning had largely re-expanded; the other two, after their im- 

 mersion for 24 hrs., were likewise plare<l in water, and in 24 hrs. 

 were considerably re-expanded, though their glands were as black 



