276 PllOCEKDTNGS OF SOCIETIES.
cortex proper, in the bud-scales of F. Cimninghamll, Hook. ; of (Inerciin ptdnncidatd, Elirh. ; Carpintis Bftnlas, L. ; Fopnlas alba, L. ; P. hybrlda, Bieb. ; P. tremida, L., and P. tremuloldes, Michx.
2. I)iti^rior cortical layer. — The two layers of cortex are easily dis- tinouishable ; the inner may sometimes form the predominant layer in the bud-scales, as in Rhannius alpina, L., Tilia parvifuUa, Ehrh. In this last tree this tissue is especinlly remarkable for the presence of large cavities filled with a viscous matter.* In Popnlns dilatata. Ait., P. bal- samifera, L., P. angidnta. Ait., P. candicans. Ait., P. Canadensis, Desf., and P. nigra, L., which have the two cortical layers scarcely distinct the one from the other, it is the inner layer, which in the bud-scales predo- minates over the outer one.
3. Older cortical layer. — This cellular tissue predominates in the bud- scales of Acer plata)ioides, L., and the different species of Sdix, — S. lanata, L., for example. When no difference exists between the two layers of the cortex, as in JEscultis Ilippocastannm, L., and Fraxiuuii excelsior, L., the entire parenchyma of the bud-scales seems to correspond to the external cortical layer.
4. Cork. — The whole of the upper and naked portion of the biul-scalea of Ulmus rnontana, Sm., consists, for the most part, of this tissue ; in their lower portion the cortex is the predominant element, and its inner tissue decomposes, in great measure, into a viscous fluid. Corylm Avel- lana, L., resembles the Elm in the consistence of its bud-scales.
5. Epidermis. — The middle scales of Jbies excelso, De Cand., as well as of other conifers, consist for the most part of an epidermis, of which the external wall is considerably thickened.
[It may be useful to give the morphological equivalents of some of the bud-scales, of which the minute anatomy has been described by Areschoug.
Stipules. — It is rather remarkable that, inasmuch as these organs are found to vary considerably in different Natural Orders, so as to afford available distinctive characters, they should take the form in the majority of our forest trees of protective scales. This is the case in the Lime {Tiliacea:); Vine {Atnpelided); Fig {Urticacers) ; ~Ei\m (^Ulmacece'); Ciiest- nut, Oak, Hazel, Beech {Cnpidiferre) ; Willow, Poplar {Salicaceae) .
Stipules and petiole combined.- — -Rose.
Petioles. — Gooseberry, Ash, Horse-chestnut. Walnut.
Blade. — Lilac, Maples (Vaccini/an Myrtdlns), L., GonifercB.
An elaborate paper on tlie naked-eye anatomy of Bud-scales, by Loefling, will be found in the ' Ama3nitates Academical,' vol. ii. ; see also
- Malpighii Opera Omnia,' toni. i. pi. x.-xiii. — W. T. D.]
��Jlroreebings of Societies.
BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE.— EDINBUKGH, 1871.
The following communications bearing upon botany were read: — Section C. Geology. — Professor Williamson, "On the Structure of
- The more external cells arc represented as containing spha:;raphides (fig. 31).
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