82. 



plate or v/ing of the scalelis wider towards the tip of the 

 pinna. The mature scale consists of a sunken funnel-shaped 

 body the lower end of which is sunken in the tissue of the 

 leaf and the upper plate-like flat portion resting on the 

 surface of the epidermis. The plate-like portion consists 

 of a peripheral, memhraneous, radially rihbedjparanchymatous 

 celled wing and a central cluster of cells, The cells of the 

 wing are thick walled and are devoid of protoplasm as are also 

 the cells of the central clustr except that the latter are 

 brown in color, The cells of the funnel-shaped body, the stalk 

 of the scale, unlike those of the plate are thin walled and 

 contain protoplasqi 8,s is indicated by the presence of large 

 nuclei. Several stages in the devel praent of the scale are 

 shown in Figs,2i)-3|,, 



SUIJMARY 

 1, Poly podium polypodioides may occur on any side of a tree 



and an at any height where the environmental conditions 



allov/, 

 2, Of the climatic factors influencing the distribution 



of the polypody, the first in importance is the evaporating 



power of the air, High evaporation entirely prevents the 



grov/th of the fern, 

 3, Light also plays a part in controlling the distribution 



of the epiphyte, Its influence is probably not direct but 



