516 SIR JOHN LUBBOCK ON STIPULES, 
younger portions of the same they measure 1-1:25 mm. long. 
As they get old, they usually crumble away, leaving only the 
thicker portion close to the petiole, and connected by a mere 
rim round the stem. 
The stems are very much flattened, thin, leaf-like, deep green, 
and more or less constricted at the nodes. 
The terminal bud is covered by numerous ocrez whether there 
are leaves present or not. Where leaves do occur they are 
revolute at the edges, very narrow, applied to the edges of the 
stem, and more or less curved over the apex of the bluntly 
tapering bud. Lateral buds arise in the axils of the ocresx, which 
the buds cover till growth pushes aside or ruptures them. The 
lateral buds often become more or less fascicled, apparently by 
the development of secondary buds from the base of the primary 
ones, after the latter lengthen into shoots. The primary or 
lowermost internodes of these shoots are undeveloped. 
According to the ‘Genera Plantarum’ (iii. p. 101), Muehlen- 
beckia platyclada is remarkable from having its branches entirely 
leafless and the ocres reduced to a transverse line. This descrip- 
tion has probably been drawn up from dried specimens. 
In &. varians, Meissn., the stems are long, slender, more or 
less prostrate, terete. The leaves alternate on the 2 plan, are 
deltoid, entire or trilobate or hastate. The stipules are adnate 
to the base of the petiole, then intrapetiolar, connate into a 
cylinder closely investing the stem, membranous and gradually 
crumbling away. 
Terminal and axillary buds are protected much in the same 
way as in W. platyclada. 
ARISTOLOCHIACER. 
The Aristolochiacee are exstipulate. 
In Asarum europeum, Linn., the winter bud is aerial and pro- 
tected by two or three amplexicaul downy or tomentose leaves 
reduced to scales. These enlarge upon the resumption of growth 
in spring, and become somewhat hooded. They are arranged on 
the 3-plan. 
The axis becomes elongated for about 2-2°5 em., and terminates 
in a pair of cordate or reniform, long-stalked, opposite leaves. 
The base of the petiole is concave, surrounding and protecting a 
terminal bud, which repeats the annual increment of growth 
the following year. On strong shoots a single flower arises in 
