296 DION^A MUSCIPULA. CHAP. XIII 



As in this case the glands on both sides are pressed 

 against the meat or insect, the secretion from the first 

 is twice as great as when a bit of meat is laid on the 

 surface of one lobe ; and as the two lobes corne into 

 almost close contact, the secretion, containing dis- 

 solved animal matter, spreads by capillary attraction, 

 causing fresh glands on both sides to begin secreting 

 in a continually widening circle. The secretion is 

 almost colourless, slightly mucilaginous, and, judging 

 by the manner in which it coloured litmus paper, 

 more strongly acid than that of Drosera. It is so 

 copious that on one occasion, when a leaf was cut 

 open, on which a small cube of albumen had been 

 placed 45 hrs. before, drops rolled off the leaf. On 

 another occasion, in which a leaf with an enclosed bit 

 of roast meat spontaneously opened after eight days, 

 there was so much secretion in the furrow over the 

 midrib that it trickled down. A large crushed fly 

 (Tipula) was placed on a leaf from which a small 

 portion at the base of one lobe had previously been 

 cut away, so that an opening was left ; and through 

 this, the secretion continued to run down the footstalk 

 during nine days, that is, for as long a time as it was 

 observed. By forcing up one of the lobes, I was able 

 to see some distance between them, and all the glands 

 within sight were secreting freely. 



We have seen that inorganic and non-nitrogenoua 

 objects placed on the leaves do not excite any move- 

 ment ; but nitrogenous bodies, if in the least degree 

 damp, cause after several hours the lobes to close 

 slowly. Thus bits of quite dry meat and gelatine were 

 placed at opposite ends of the same leaf, and in the 

 course of 24 hrs. excited neither secretion nor move- 

 ment. They were then dipped in water, their sur- 

 faces dried on blotting paper, and replaced on the samo 



