CoAP. VI.] DIGESTION. 91 



absorbed little of the liquefied tissue, or had been little af- 

 fected by it. 



Phosphate of Lime. As we have seen that the tentacles 

 of the first set of leaves remained clasped for nine or ten days 

 over minute fragments of bone, and the tentacles of the 

 second set for six or seven days over the same fragments, I 

 was led to suppose that it was the phosphate of lime, and 

 not any included animal matter, which caused such long- 

 continued inflection. It is at least certain from what has 

 just been shown that this cannot have been due to the pres- 

 ence of the fibrous basis. With enamel and dentine (the 

 former of which contains only 4 per cent, of organic matter) 

 the tentacles of two successive sets of leaves remained in- 

 flected altogether for eleven days. In order to test my belief 

 in the latency of phosphate of lime, I procured some from 

 Prof. Frankland absolutely free of animal matter and of any 

 acid. A small quantity moistened with water was placed on 

 the discs of two leaves. One of these was only slightly 

 affected; the other remained closely inflected for ten days, 

 when a few of the tentacles began to re-expand, the rest be- 

 ing much injured or killed. I repeated the experiment, but 

 moistened the phosphate with saliva to insure prompt in- 

 flection; one leaf remained inflected for six days (the little 

 saliva used would not have acted for nearly so long a time) 

 and then died ; the other leaf tried to re-expand on the sixth 

 day, but after nine days failed to do so, and likewise died. 

 Although the quantity of phosphate given to the above .four 

 leaves was extremely small, much was left in every case un- 

 dissolved. A larger quantity wetted with water was next 

 placed on the disc of three leaves; and these became most 

 strongly inflected in the course of 24 hrs. They never re- 

 expanded; on the fourth day they looked sickly, and on the 

 sixth were almost dead. Large drops of not very viscid fluid 

 hung from their edges during the six days. This fluid was 

 tested each day with litmus paper, but never coloured it; 

 and this circumstance I do not understand, as the super- 

 phosphate of lime is acid. I suppose that some superphos- 

 phate must have been formed by the acid of the secretion 

 acting on the phosphate, but that it was all absorbed and in- 

 jured the leaves; the large drops which hung from their 

 edges being an abnormal and dropsical secretion. Anyhow, it 



