136 DROSERA ROTUNDIFOLIA. [Chap. VII. 



tain whether they induced inflection, Hnlf-mininis of a solution 

 of one part of the sulphate of ammonia to 437 of water were 

 placed on the tiiscs of seven leaves, so that each received ^n 

 of a grain, or .OUTo mg. After 1 hr. the tentacles of live of them, 

 as well as the blade of one, were strongly inflected. The leaves 

 were not afterwards observed. 



Citrate of Ammonia. Half-minims of a solution of one part to 

 437 of water were placed on the discs of six leaves. In 1 hr. the 

 short outer tentacles round the discs were a little inflected, wit> 

 the glands on the discs blackened. After 3 hrs. 25 m. one leaf had 

 its blade inflected, but none of the exterior tentacles. All six 

 loaves remained in nearly the .name state during the day, the sub- 

 ninrginal tentacles, however, becoming more and more inflected. 

 After 23 hrs. three of the leaves had their blades somewhat in- 

 flected, and the submarginal tentacles of all considerably inflected, 

 but in none were the two, three, or four outer rows affected. I 

 have rarely seen cases like this, except from the action of a decoc- 

 tion of grass. The glands on the discs of the above leaves, instead 

 of being almost black, as after the first hour, were now, after 23 

 hrs., very pale. I next tried on four leaves half-minims of a 

 weaker solution, of one part to 1312 of water (1 grain to 3 oz.) ; so 

 that each received -j-^j^ of a grain (.0225 mg.). After 2 hrs, 18 m. 

 the glands on the disc were very dark-coloured; after 24 hrs. two 

 of the leaves were slightly afTccted; the other two not at all. 



Acetate of Ammonia. Half-minims of a solution of about one 

 part to 109 of water were placed on the discs of two leaves, both 

 of which were acted on in 5 hrs. 30 m., and after 23 hrs. had every 

 single tentacle closely inflected. 



Oxalate of Ammonia. Half-minims of a solution of one part 

 to 218 of water were placed on two leaves, which, after 7 hrs., be- 

 came moderately, and after 23 hrs. strongly, inflected. Two other 

 leaves were tried witJi a weaker solution of one part to 437 of 

 water; one was strongly inflected in 7 hrs.; the other not until 

 30 hrs. had elapsed. 



Tartrate of Ammonia. Half-minims of a solution of one part 

 to 437 of water were placed on the discs of five leaves. In 31 m. 

 there was a trace of inflection in the exterior tentacles of some of 

 the leaves, and this became more decided after 1 hr. with all the 

 leaves; but the tentacles were never closely inflected. After 8 hrs, 

 30 m. they began to re-expand. Next morning, after 23 hrs., all 

 were fully re-expanded, excepting one which was still slightly in- 

 flei'ted. The shortness of the period of inflection in this and the 

 following case is remarkable. 



Chloride of Ammonia. Half-minims of a solution of one part 

 to 437 of water were placed on the discs of six leaves. A decided 

 degree of inflection in the outer and submarginal tentacles was per- 

 ceptible in 25 m.; and this increased during the next three or four 

 hours, but never became strongly marked. After only 8 hrs, 30 m. 

 the tentacles began to re-expand, and by the next morning, after 

 24 hrs., were fully re-expanded on four of the leaves, but still 

 slightly inflected on two. 



