322 Earl Harrington Foote 



shows a condition strikingly like velutina save that the bands 

 are more distinct (Plate XIII, figs. 1-8). 



The composition of the annual ring presents certain significant 

 features. The spring wood which in all three is not sharply 

 defined, in inibricaria appears in the form of a fairly regular 

 band of large tracheae of nearly uniform size extending completely 

 across the space between two broad medullary rays, with very 

 little of wood masses included. In velutina the tracheae are not 

 so uniform in size and show a tendency to be grouped together 

 in irregular shaped areas interspersed with wood masses. In 

 Leana the vessels are perhaps more nearly uniform in size as in 

 imhricaria but they show a tendency toward bunching as in 

 velutina. The summer wood in imhricaria is nearly solid, broken 

 rather inconspicuously by small amounts of wood parenchyma 

 forming long narrow tangential lines. A few small tracheae 

 appear distributed radially. In velutina the masses of summer 

 wood are as a rule relatively broader and are not nearlj' so dense, 

 the blocks of wood fibres being broken up by the more niimerous, 

 broader and more conspicuous tangential bands of wood paren- 

 chyma. The summer wood in Lea7ia presents a condition closely 

 approximating that in velutina save that the tangential bands 

 of wood parenchyma are slightly less numerous and the growth 

 ring is not so wide. The growth ring is narrower in imhricaria 

 than it is in either of the others. 



Microscopic Studies 



Sections in transverse, tangential, and radial planes were 

 made with a sliding microtome from stems of various sizes up to 

 2i cm. in diameter. A part of these sections were cut from 

 living material, the sections being transferred to 70 per cent 

 alcohol and then brought into water for staining; and a part 

 were made from material fixed in picro-corrosive and imbedded 

 in celloidin according to Jeffrey's method. i- All were stained 

 with Ehrlich's hsematoxylin and safranin. 



i'^ Botanical Gazette, vol. xxxvii, pp. 456-461, 1904. 



