Bifoliar Sjnirs into ordinary Buds. 261 



the leaves of the original fascicle had fallen off; and it is 

 further to he noted that tlie spirally-arranged foliage- leaves 

 are of the same character — comparatively short — as in my 

 case. 



HaherlandVs Vieius on the Physiological Functions of 

 Plant Tissues. * By G. F. Scott Elliot, B. A. 



(Read July 9, 1885.) 



Each cell in the living plant is, in his view, specially 

 devoted to some primary function, though it may also have 

 one or more minor functions. Thus it is on the principle 

 of division of labour that the morphological differentiation 

 of the plant is based (Schleiden and Nageli). And the 

 principal object of the paper is to explain the anatomical 

 characters of the tissues by their physiological functions. 



He accordingly adopts a classification of the tissues 

 founded on their functions, as follows : — 



I. Skin System, including epidermis and periderm. 

 II. Mechanical.—RQ.&t (i.e., hard bast), libriform cells, 

 collenchyma and sclerenchyma. 

 III. Nutritive Tissues, divided into — 



(1) Absorption tissues (epithelium of roots and root- 



hairs). 



(2) Assimilation system (chlorophyll or palisade 



parenchyma). 



(3) Conduction system (conduction parenchyma and 



bundles, the parenchymatous sheaths, laticiferous 

 vessels). 



(4) Eeservation tissues (those tissues which in buds 



and seeds are devoted to storing material). 



(5) Aeration system (intercellular spaces, stomata, 



and lenticels). 

 The embryological tissues adopted are — 



Protodermis, which corresponds to dermatogen. 

 Cambium, by which he seems to mean the original 



meristem cells of the future bundle (Procambium). 

 Ground parenchyma, i.e., what remains after these two 

 have been deducted. 



* Haberlandt, G., Physiologische Pflanzen Anatomic, Leipzig, 1884. 

 TRANS. ROY. BOX. SOC, VOL. XVI. 8 



