170 DROSERA ROTUNDIFOLIA. [Chap. IX. 



fii-st increased, but soon languished, and after between 15 and 20 

 minutes ccascti ; whilst those in the water were still acting vigor- 

 ously. The white corpuscles of the blood of a frog, and the cilia 

 on two infusorial animals, a Param&ecium and Volvox, were simi- 

 larly affected by the poison. Dr. Fayrer also found that the muscle 

 of a frog lost its irritability after an immersion of 20 m. in the 

 solution, not then responding to a strong electrical current. On 

 the other hand, the movements of the cilia on the mantle of an 

 Unio were not always arrested, even when left for a considerable 

 time in a very strong solution. On the whole, it seems that the 

 poison of the cobra acts far more injuriously on the protoplasm of 

 the higher animals than on that of Drosera. 



There is one other point which may be noticed. I have occasionally 

 observed that the drops of secretion round the glands were ren- 

 dered somewhat turbid by certain solutions, and more especially 

 by some acids, a film being formetl on the surfaces of the drops; 

 but I never saw this effect produced in so conspicuous a manner 

 as by the cobra poison. When the stronger solution was employed, 

 the drops appeared in 10 m. like little white rounded clouds. After 

 48 hrs. the secretion was changed into threads and sheets of a 

 membranous substance, including minute granules of various 

 sizes. 



Camphor. Some scraped camphor was left for a day in a bottle 

 with distilled water, and then filtered. A solution thus made is 

 said to contain yi^ o^ i*^ weight of camphor; it smelt and tasted 

 of this substance. Ten leaves were immersed in this solution; 

 after 15 m. five of them were well inflected, two showing a first 

 trace of movement in 11 m. and 12 m. ; the sixth leaf did not 

 begin to move until 15 m. had elapsed, but was fairly well in- 

 flected in 17 m. and quite closed in 24 m.; the seventh began to 

 move in 17 m., and was completely shut in 26 m. The eighth, 

 ninth, and tenth leaves were old and of a very dark red colour, 

 and tiiese were not inflected after an immersion of 24 hrs.; so that 

 in making experiments with camphor it is necessary to avoid such 

 leaves. Some of these leaves, on being left in the solution for 4 

 hrs., became of a rather dingy pink colour, and secrete<l much 

 mucus; although their tentacles were closely inflected, the pro- 

 toplasm within the cells was not at all aggregate<l. On another 

 occasion, however, after a longer immersion of 24 hrs., there was 

 well-marked aggregation. A solution made by adding two drops 

 of camphorate<l spirits to an ounce of water did not act on one 

 leaf; whereas thirty minims added to an ounce of water acted on 

 two leaves immersed together. 



M. Vogel has shown ' that the flowers of various plants do not 

 wither so soon when their stems are placed in a solution of cam- 

 phor as when in water; and that if already slightly withered, tbey 

 recover more quickly. The gennination of certain seeds is also ac- 

 celerated by the solution. So that camphor acts as a stimulant, 

 and it is the only known stimulant for plants. I wished, there- 



Onnlfner'B rhronlcle,* 1874, tlons were made in 1798 by B. 8. 

 p. G71. Nearly similar observa- Barton. 



