164 DROSERA ROTUNDIFOLIA. Chap. Vn. 



soon re-expanded ; (9), (10), (11) and (12) none inflected, though 

 observed for twenty-four hours. 



Comparing the states of the twelve leaves in water with those 

 in the sohition, there could be no doubt that in the latter a larger* 

 number of tentacles were inflected, and these to a greater degree ; 

 but the evidence was by no means so clear as in the former ex- 

 periments with stronger solutions. It deserves attention that the 

 inflection of four of the leaves in the solution went on increasing 

 during the first 6 hrs., and with some of them for a longer time ; 

 whereas in the water the inflection of the three leaves which 

 were the most affected, as well as of all the others, began to de- 

 crease during this same interval. It is also remarkable that the 

 blades of three of the leaves in the solution were slightly in- 

 flected, and this is a most rare event with leaves in w\ater, 

 though it occurred to a slight extent in one (No. 1), which 

 seemed to have been in some manner accidentally excited. All 

 this shows that the solution produced some effect, though less 

 antl at a much slower rate than in the previous cases. The 

 small effect produced may, however, be accounted for in large 

 part by the majority of the leaves having been in a poor con- 

 dition. 



Of the leaves in the solution. No. 1 bore 200 glands and received 

 4s 000 ^^ ^ grain of the salt. Subtracting the seventeen tentacles 

 which were not inflected, each gland could have absorbed only 

 the "sYs+ooo of ^ grain (-00000738 mg.). This amount caused 

 the tentacle bearing each gland to be greatly inflected. The 

 blade was also inflected. 



Lastly, eight leaves were immersed, each in thirty minims of a 

 solution of one part of the phosphate to 21,875,000 of water (1 gr. 

 to 5000 oz.). Each leaf thus received « o^oo ^^ ^ grain of the salt, 

 or '00081 mg. I took especial pains in selecting the finest leaves 

 from the hot-house for immersion, both in the solution and the 

 w^ater, and almost all proved extremely sensitive. Beginning as 

 before with those in the solution : — 



(1) After 2 hrs. 30 m. all the tentacles but twenty- two in- 

 flected, but some only sub-inflected ; the blade much inflected ; 

 after 6 hrs. 30 m. all but thirteen inflected, with the blade 

 immensely inflected ; and remained so for 48 hrs. 



(2) No change for the first 12 hrs., but after 24 hrs. all the 

 tentacles inflected, excepting those of the outermost row, of which 

 only eleven were inflected. The inflection continued to increapc, 

 and after 48 hrs. aU the tentacles except three were inflected. 



