Shrubs and Vines 
and incisions correspond with surprising exactness. 
But in the sweet fern, the incisions, which are very 
deep, and reach almost to the mid-rib, are as uniformly 
alternate on the two sides. A little thought will ex- 
plain this almost solitary exception to the rule. The 
incisions are so numerous and deep that the mid-rib 
would be much weakened and liable to break if they 
exactly coincided, but acquires rigidity by the simple 
device of alternating the incisions, whereby the mid- 
rib is strengthened on one side when weakened on 
the other. I shall always have more respect for this 
despised weed after such proof of painstaking in its 
construction. 
For those whose grounds adjoin a lake or pond, the 
familiar button-bush, Cephalanthus occidentalis, is worth 
considering. It grows in water, has luxuriant, dark- 
green foliage, and showy clusters of white flowers, 
densely massed into spherical heads ; the leaves are op- 
posite or whorled. 
I have seen no shrub in the Park whose glossy ever- 
green foliage surpasses that of Wlahonia aquifolium, per- 
haps the most desirable low species of its sort. The 
leaf is pinnate, and each leaflet is the duplicate of the 
English holly leaf, but with a lustre that can scarcely be 
rivalled ; and being in the barberry family, it is often 
called holly-leaved barberry. It comes from the Far 
West, and, though called evergreen in the books, it does 
not prove so in the Park. Its short racemes of small 
yellow flowers are produced early in spring, and followed 
by blackish berries. It should be included in every list 
of lawn shrubbery, however small. 
I7I 
