182 The Botanical Gazette. (June, 
(Ailanthus glandulosus Desf.) or only with three in each 
scar (species of Fuglans, Pterecarya, Carya, figs. 20-30. 
5. Inother scars of heart-shaped form, and in the great ma- 
jority of those which are lunate, the fibrovascular bundles form 
small circular areas. These show a sufficient constancy in their 
number within the same scar if only the more fully developed 
scars be examined and if quite a number of twigs be drawn 
into consideration, so that a division into scars with only three 
sets (Ulmus fulva, Michx., fig. 3; Celtis occidentalis Linn., 
fig. 4; Viburnum molle, fig. 10; Nyssa~multifiora Wang., fig. 
11; Spiraea opulifolia Linn., fig. pk Hamamelis Virginica 
Linn. ), and into scars having five rounded Sets of fibrovascu- 
lar bundles is possible (As#mina triloba Dunal., fig. 1; Rhus 
Toxicodendron Linn., fig.7; species of Aisqulus). ‘Some- 
smaller scars, or on the weaker twigs. In other species the 
number usually five is occasionally raised to seven (Sambucus 
Canadensis Linn., fig. 37). The two outer sets are often 
more or less approximated while the median fifth set is left 
more isolated (Gymnocladus Canadensis Lam., fig. 31; AG” 
saccharinum Wang.). How far this character remains con 
stant and therefore of value for present purposes has not 
been determined. 
In species with opposite leaves it is also frequently of = 
tance to notice if the edges of the petiole scars are sufficiently 
extended laterally almost or quite to meet (Cornus florida 
Linn., fig. 35; Cornus paniculata LHer., fig. 36.; Ngee 
ne ais a Moench, fig, 18; Acer saccharinum Wan ng.) o 
they remain considerably separated from each other (species 
of ee Euonymus atropurpureus Jacq., fig. 19; 2 seca 
of Aesculu ts 
ll A third means for further classifying ligneous pla” 
is gs character of their winter buds. b 
These may be so situated, either concealed in the riot 
atanee of the petiole scar itself, or covered by the set 
end of the scar, that the development of these buds ies 
spring requires the splitting of the scar, or at 
marked forcing back of the anterior end of the same 
permum Canadense aoe fig. 12; Robinia Pseudacacta 
Rhus aromatica Ait., fig. 16. igs 
2. At times the bade are sunk into the bark of the Wie" 
Linn. ’ 
