152 Vaizey. — On the Absorption of Water in Mosses. 
easy by the external walls being slightly changed in such 
a way as to make their power of imbibition greater. This 
change appears to be similar to, if not identical with, ligneous 
change. As a result of this condition of the cell-walls, the 
leaves are the chief organs for absorbing water as well as 
for carrying on assimilation in the oophyte. 
In the sporophyte the external cell-walls are not only 
cuticularized, but there is a distinct cuticle present, con- 
sequently water can only be absorbed normally at one point, 
by the foot which is inserted in the tissues of the oophyte ; 
in experiment, of course it is absorbed at a cut surface. 
Since water can in the sporophyte only be absorbed at one 
point, there must be arrangements for conveying it to other 
parts. This is done as I have shown 1 by a transpiration- 
current which passes up the seta to the apophysis (the organ 
of assimilation), where transpiration takes place through the 
stomata. 
1 Vaizey, J. Reynolds, Note on the Transpiration of the Sporophore of the 
Musci, in Annals of Botany, Vol. I, No. 1 (1887). 
St. Peter’s College Cambridge. 
