2 TO 
Hill and de Frame. — On the 
Pinus laricio , Poir, is also described by Dangeard. 1 The cotyledons 
vary from eight to ten, and the vascular rearrangements show the same 
variations as we have found in other species of the genus. 
Larix. 
The structure of the seed-leaves requires but a short description. 
Resin ducts have not been observed in L. Occident alis ; they are present in 
L. leptolepis and L. europaea, in which plants each cotyledon has two canals, 
situated one in each dorsal corner of the leaf. Each seed-leaf has a single 
vascular strand ; there may be a little variation in this respect, for one plant 
showed two separate bundles in one cotyledon similar to what has been 
described above for Pinus montana , var. gallica and P. contorta , var. 
Murray ana . The vascular bundle is endarch and collateral throughout 
the whole length of the member, and transfusion tracheides have not been 
observed. Finally, the cotyledons tend to fuse laterally at their bases to 
form more or less complete tubes. 
Larix occidentalism Nutt. The only seedling available had six cotyle- 
dons, each of which had a single endarch collateral bundle. The vascular 
rearrangements all took place in the hypocotyledonary axis and resembled 
those described for Pinus Gerardiana and P. halepensis very closely. Thus 
of the six seed-leaves, the behaviour of the bundles showed one to be 
a whole-cotyledon, four to be half-cotyledons, and the remaining one 
subsidiary. 
Larix leptolepis does not differ in any essential feature from L. occi- 
dentals. 
Larix europaea, DC. 
Series A and B. Six seed-leaves were present, the bundles of which 
showed the same rearrangements as have been described for Abies pectinata 
and other plants ; in brief, two pairs of bundles rotated so as to form the 
two poles of the diarch root, and the remaining bundles merely fused on to 
the others, taking no part in the transition. Dangeard 2 states that the 
transition resembles Picea alba . 
Series C. In this seedling there were seven cotyledons, the bundles 
of which behaved somewhat differently from any of the foregoing plants. 
The first figure of Diagram 8 shows the seed-leaf-traces a, b ... g arranged 
in a zone in the upper part of the hypocotyl. On tracing the strands 
downwards, b and c approach one another and each fuses with the vascular 
tissue on either side, their protoxylems rotate towards each other and 
outwards and form a pole of the triarch root, the strand b contributes most 
of the protoxylem. These strands are therefore derived from half-cotyle- 
dons. The bundle a very soon bifurcates, one half passing over and fusing 
1 Dangeard : Le Botaniste, iii, 1892. 
2 loc. cit. 
