98 
Ampelidece. 
Gaudichaud in his memoir (“ Recherches,” plate xiii, fig. 5, 
p. 109) gives a figure of the Cissus hydrophora as one of the 
common lianas of the Brazil, but I am not sure whether it 
occurs amongst the ropes which reach this country. It is 
described by M. Netto (Annales des Sciences, 5th ser. Bot. 
t. vi., p. 320 ; Comptes Rendus, tom. 62, p. 1076,) and a 
short summary is worth transcribing, as he had the advan- 
tage of studying the living plant. v 
In the section of a young stem, beginning with the bark, 
we have first a suberous layer, then a thick cellular layer 
containing very little chlorophyll ; and having at the side 
nearest the bark a mass of dotted cells whose walls become 
very thick. On the inner edge of this cellular layer we 
meet with a number of liberian bundles in front of some 
woody bundles ; the latter are strikingly subdivided by the 
adjacent parenchyma into separate groups so as to cause it 
to look more like the arrangement generally seen in a 
monocotyledonous plant. 
M. Netto mentions that the structure of the woody mass 
is even more remarkable, since in the place of the ordinary 
medullary rays, cellular bands are projected from the bark 
towards the pith which form cortical rays. Another pecu- 
liarity of the woody part is that, notwithstanding it may 
be two years old, the woody fibres are so loosely held to- 
gether that they readily detach themselves from the cellular 
tissue in which they are imbedded. The stem must be at 
least three years old before it attains anything like con- 
sistency; this weakness, as contrasted with other lianas, 
probably leads to its not being so frequently used for pack- 
ing purposes. 
There is one histological character however presented by 
this liana which will lead to its identification, and that is 
the abundant quantity of raphidian crystals contained in all 
parts of the stem. M. Netto describes the form of these 
