258 Boodle and Worsdell. — On the 
from each of the two first leaves in the act of passing into 
the centre, and, alternating with these, two bundles from 
each cotyledon coming in to join the four central bundles. 
These two cotyledonary bundles may either remain as two 
separate though closely-placed bundles, or they may fuse 
into one ; as they pass in together their protoxylems seem 
to turn towards each other. A little below, the transition 
from stem to root takes place. 
As far as could be made out, this seems to follow the 
dicotyledonous mode ; the four bundles from the plumular 
stem fuse together in twos, their xylems severally ‘ rotating ’ ; 
the two bundles from the cotyledons, each of which represents 
really two distinct bundles, remain as they are, their xylems 
simply 4 rotating 5 ; the phloem, however, separates, and each 
half fuses with the phloem of the plumular bundle on each 
side. So that thus a tetrarch root is formed, with four 
primary xylem-, and four primary phloem-groups. 
In Gnetum there is a difference; according to Bower 1 the 
xylem of only two of the bundles rotates on its axis, while 
the other bundles, of which there seem to be several, do not 
rotate, but pass down and finally become lost in the cambium 
of the root. The phloem of each of the rotating bundles 
divides into two, which mutually fuse to form the primary 
phloem ; this corresponds with the two cotyledonary bundles 
in Casnarina , whose phloem divides in the same manner. 
In Cctsuarina , the endodermis appears just after the cotyle- 
donary bundles have passed in, and there is a peri cycle of 
two to three layers. Cuticularization in the endodermis also 
extends to the tangential walls, as in Gnetum . 
Summary. 
The result of our anatomical investigations confirms what 
previous authors have stated as to the rather isolated position 
which Casnarina holds among Dicotyledons, by reason of the 
1 Loc. cit, id. 285. 
