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). 



