Cuar. VI. DIGESTION. 109 
They quickly began to re-expand; five of them on 
the second day, and the other two on the third day. 
On all seven leaves the fibrous tissue was converted 
into perfectly transparent, viscid, more or less lique- 
fied little masses. In the middle, however, of one, 
my son saw under a high power a few corpuscles, 
with traces of fibrillation in the surrounding trans- 
parent matter. From these facts it is clear that the 
leaves are very little excited by the fibrous basis of 
bone, but that the secretion easily and quickly lique- 
fies it, if thoroughly decalcified. The glands which 
had remained in contact for two or three days with 
the viscid masses were not discoloured, and appa- 
rently had absorbed little of the liquefied tissue, 
or had been little affected by it. 
Phosphate of Lime.—As we have seen that the ten- 
tacles 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 in- 
flection. It is at least certain from what has just been 
shown that this cannot have been due to the presence 
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 inflected altogether for eleven 
days. In order to test my belief in the potency of 
phosphate of lime, I procured some from Prof. Frank- 
land 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 
