( 29 ) 
the axis of the branch, sometimes at a right angle ( Fagus , Celastrus ); or 
the bnd is appressed, the axis being parallel to the shoot ( Cornus , Virburnum , 
Salix*). 
The axis of a bud wh'ch stands straight above the leaf-scar is radial, 
it points to the centre of the branch ; but in some species, particularly in 
those with bifarious buds ( Morus , Celtis , Ulmus , Tilia ) the bud stands not 
right above the leaf-scar but a little aside, then the direction of the bud is 
oblique, and its axis is tangential, it strikes the periphery of the shoot. 
The axis itself is sometimes not straight, but bent ( Celtis , Ulmus). 
THE SCALES OF THE BUD. 
The number of scales is not always definite. It is said to be ten in 
Cary a alba ; and yet I have counted in the upper bud a greater number, 
sometimes even as many as twenty, though in many species the number is 
constant. Salix has the bud covered by a single hood-like scale, Tilia has 
two, the inner one larger and enveloping the bud with overlapping margins. 
In Negundo and Staphylea one pair is visible, the inner ones are herbaceous 
and pass into leaves. Acer clasycarpun has four pairs, and Acer sacchari- 
num eight pairs, Aesculus four opposite rows of five to six scales each. 
Fraxinus and Euonymus have three pairs. 
The arrangement of the scales follows the rule of Phyllotaxis. In the 
bifarious species the scales are arranged in two rows, and there are four 
scales in each row (in Ulmus , Celtis , Morus). In those with five buds in 
two circuits the buds have the same arrangement, they are imbricate. f 
The form of the scales is often variable in the same species and the 
same individual. It is mostly ovate and convex, pointed ( Aesculus , Popu- 
lus , Quercus coccinea), or mucronate ( Crataegus ), or obtuse ( Corylus , 
Quercus nigra). The scales are pinnately grooved at the upper end in 
many species with pinnate leaves ( Fraxinus , Juglans , Cary a amara). 
The surface is smooth ( Crataegus, Quercus rubra), or pubescent (Fagus, 
Carya alba), or tomentose ( Rhus glabra , Ulmus fulva, Quercus coccinea ), 
or sericeous ( Dirca ), or velvety ( Asimina ), or furfuraceous ( Carya 
amara). The color is mostly brown, but sometimes green (Euonymus), 
yellow (Carya amara, Dirca, Liriodendron ), rusty red (Zanthoxylon), 
bluish black ( Fraxinus sambucifolia), purplish brown (Asimina). Some 
have a darker colored zone along the margin (Morus). 
VERNATION. 
When we cut a bud horizontally, we observe the inner arrangement, 
the position of the leaves and their parts. In the species with decussate 
*In Salix cordata Yar. angusta, only the flower-buds are somewhat spreading. 
fM. C. De Candolle (Memoir e sur la famille des Juglandees) calls the buds of Carya 
olivaeformis and amara decussate. That may be true concerning the lateral buds ; 
in the terminal buds, as many as I have examined, I have found the phyllotaxis 
invariably 2-5. 
The same author differs from other botanists in his phyllotaxis, since he 
passes from one scale, bud or leaf to the next on the longest and not on the shortest 
line, and thus, of course, makes three circuits instead of two. 
