232 SIR JOHN LUBBOCK ON STIPULES, 
which helps to constitute a very efficient protection. Zueryphia 
pinnatifolia is provided with similar, but smaller, glands. The 
genus Nuttallia is described by Bentham and Hooker as ex- 
stipulate. N. cerasiformıs, however, appears to present a very 
interesting gradation. The winter-bud is covered with numerous 
Leaf of Nutfallia cerasiformis.—a. With entire sheath. b. Showing indications 
of stipules. c. With stipules in ultimate form. 
scales, which are leaves wholly reduced to their sheaths : the outer 
ones very short, rounded, ovate, or triangular, not lengthening 
when growth commences: the inner ones lengthen, becoming 
linear, cuspidate, concave, rolled round the bud, pale green, 
almost colourless, membranous and ciliate at the margin. 
The first leaf in the bud having a lamina is spathulate, with 
the petiole transformed into a grooved sheath, membranous at 
the margin right up to the base of the lamina; the second and 
third leaves have a similar but shorter sheath, and oblong lamina ; 
the fourth leaf is oblong or oblanceolate, with the membranous 
sheath partly separated from the petiole, and forming stipules 
still adnate for the greater part of their length; the fifth and 
sixth leaves are similar with shorter petioles, and shorter, but 
more evident, stipules. Here, then, we have in the bud a gradual 
transition from leaves wholly reduced to sheaths, to those with a 
lamina and a sheath, then to those with a lamina, petiole, and 
