342 BOTANICAL GAZETTE [NOVEMBER 
united and formed one large area on the dorsal side of the 
phloem and pericycle beneath the endodermis. 
5. No epidermal hairs are present onthe bud scales. All the 
scales are fringed with thin walled, hypha-like, marginal hairs, 
through which the resin diffuses to the exterior of the scales, 
until the bud is covered with a layer of resin sufficiently thick 
to prevent any further transpiration of moisture and exudation 
of resin. 
6. Resin canals are usually present in all of the bud scales. 
Cross sections of many scales show from two to six resin canals. 
7. The terminal or leader shoots, have no epidermal hairs. 
Epidermal hairs are present only on the one to three-year old 
lateral shoots. 
8. Resin vesicles or blisters are formed only in the primary 
cortex and in those parts of the original resin canals which have 
not been disturbed by the unequal peripheral growth of the 
bark, cork cambium, and the formation of tyloses. The ves- 
icles originate and increase in size by the radial and tangential 
division of the lining cells of the undisturbed part of the resin 
canal. 
g. The normal wood of A. dalsamea contains no resin canals. 
Diseased organs. 
10. Fewer Stomata are present on the diseased leaves, and 
their distribution is similar to that of the normal. 
11. Hypodermal strengthening cells are present, especially 
in the basal half of the leaf; they are more irregular in their 
form and size; and are often found in nests and groups. 
12. The transfusion tissue is nearly always present, often in 
one to three small areas on the dorsal side of the phloem. The 
cells of the diseased transfusion tissue usually have simple as 
well as bordered pits. 
13. The diseased buds are covered over with a greater NUM” 
: ber of bud scales, which are smaller than the normal. The dis- _ 
eased scales, like the normal, are fringed with marginal hairs 
— the buds are resin covered i in winter. 
