CHAP. VIII. THE EFFECTS OF ACIDS. 193 



was no inflection for about 12 hrs.; but after 23 hrs. almost all 

 the tentacles were inflected. Three leaves were likewise im- 

 mersed in unboiled linseed oil, and soon became somewhat, and 

 in 3 hrs. greatly, inflected. After 1 hr. the secretion round the 

 glands was coloured pink. I infer from this latter fact that the 

 power of linseed oil to cause inflection cannot be attributed to 

 the albumin which it is said to contain. 



Carbolic Acid. Two leaves were immersed in sixty minims of 

 a solution of 1 gr. to 437 of water ; in 7 hrs. one was slightly, 

 and in 24 hrs. both were closely, inflected, with a surprising 

 amount of mucus secreted. These leaves were washed and left 

 for two days in water ; they remained inflected ; most of their 

 glands became pale, and they seetned dead. This acid is 

 poisonous, but does not act nearly so rapidly or powerfully as 

 might have been expected from its known destructive power on 

 the lowest organisms. Half-minims of the same solution were 

 placed on the discs of three leaves ; after 24 hrs. no inflection of the 

 outer tentacles ensued, and when bits of meat were given them, 

 they became fairly well inflected. Again half-minims of a 

 stronger solution, of one part to 218 of water, were placed on the 

 discs of three leaves ; no inflection of the outer tentacles ensued ; 

 bits of meat were then given as before ; one leaf alone became 

 well inflected, the discal glands of the other two appearing 

 much injured and dry. We thus see that the glands of 

 the discs, after absorbing this acid, rarely transmit any motor 

 impulse to the outer tentacles; though these, when their own 

 glands absorb the acid, are strongly acted on. 



Lactic Acid. Three leaves were immersed in ninety minims of 

 one part to 437 of water. After 48 m. there was no inflection, 

 but the surrounding fluid was coloured pink; after 8 hrs. 

 30 m. one leaf alone was a little inflected, and almost all 

 the glands on all three leaves were of a very pale colour. 

 The leaves were then washed and placed in a solution (1 gr. 

 to 20 oz.) of phosphate of ammonia; after about 16 hrs. there 

 was only a trace of inflection. They were left in the phosphate 

 for 48 hrs., and remained in the same state, with almost all 

 their glands discoloured. The protoplasm within the cells 

 was not aggregated, except in a very few tentacles, the glands 

 of which were not much discoloured. I believe, therefore, 

 that almost all the glands and tentacles had been killed by 

 the acid so suddenly that hardly any inflection was caused. 

 Four leaves were next immersed in 120 minims of a weaker 

 solution, of one part to 875 of water; after 2 hrs. 30 m. the 

 surrounding fluid was quite pink ; the glands were pale, but 



