Cunninghdmia sinensis. 595 
they were present on one side only, and that generally the lower one, as 
inferred from the outgoing leaf traces. Fig. 2, Plate XXXI, shows one of 
the rays with marginal tracheids under a moderate degree of magnification. 
The ray in question passes through three annual rings, of which the inner- 
most (on the left of the figure) is considerably narrower than the remaining 
two. In this example the marginal tracheids appear on one side of the 
ray only, and are confined to the two internal annual rings. In other cases 
marginal tracheids have been found in the outer ring as well. Fig. 3, 
Plate XXXI, shows a portion of the same ray illustrated in the last figure, 
covering the median annual ring, more highly magnified. It is now possible 
to distinguish clearly that the marginal ray-cells present characteristic 
features on one side of the ray, in the absence of the protoplasm found in 
the remaining cells of the ray, and their relation to the tracheids of the 
wood by typical bordered pits, smaller in size than those which connect 
tracheid with tracheid. Fig. 4, Plate XXXI, shows a part of Fig. 3, 
still more highly magnified. In this figure it is possible not only to 
make out the connexion of the marginal ray-tracheids with the tracheids 
of the wood by means of typical bordered pits, but also the fact that the 
ray-tracheids are related to the protoplasmic ray-cells along their lower 
horizontal wall by unilateral bordered pits similar to those found in the 
horizontal walls of ray-tracheids in Finns , where they come in contact with 
parenchymatous ray-cells. In only one or two instances have bordered 
pits been found in the terminal walls connecting the ray-tracheids with one 
another. Generally these walls are entirely free from pitting. The ray- 
tracheids of Cunninghamia resemble those described by Penhallow in 
Cupressus , Juniperus , and Thuya in being without the dentate projections 
characteristic of the Hard Pines, and found also by De Bary in the case of 
Sciadopitys (loc. cit ). 
The discovery of ray-tracheids in the wood of the branch of Cunning- 
hamia under discussion led to the examination of the rest of the woody 
cylinder for the same phenomenon. It was found that the rays, with 
tracheids, occurred in only about half of the circumference of the stem, and 
were quite absent in the remainder. The half of the woody cylinder without 
the rays possessing ray-tracheids showed clearly the presence of wound- 
cap, consisting of three years’ growth and beginning inwardly with a typical 
wound-callus. Fig. 5, Plate XXXI, shows a longitudinal section through 
this region. Near the middle of the section is a dark stripe, representing the 
wound-callus. On the left of this is the normal wood formed previously to 
injury. On the right is the wound-cap, consisting of three years’ growth, 
terminating outwardly in the phloem, which appears as a dark stripe. It 
is to be noted that the wound-cap is characterized by a considerable increase 
in the number of medullary rays present over that found in the normal 
wood. Fig. 6 , Plate XXXI, shows a more magnified image of the radial 
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