ABSORPTION OF RAIN AND DEW BY GREEN PARTS OF PLANTS. 173 



Plant 



Proportional 

 No. of 

 Stomata 



ourtace on 

 Water 



Loss 

 per Cent. 



Apparent 



Condition 



Berberis Aquifohum . 



0 



Upper 



26-31 



Fresh 





50 



Lower 



13-38 



Fresh 





In air 



— 



49-10 



Withered 



Ficus Canca 



0 



Upper 



1-52 



Fresh 



55 u • 



100 



Lower 



5-23 



Fresh 



»» »» • • 



In air 



— 



73-95 



Dry and brittle 



Ligustrum vulgare . 



0 



Upper 



7-93 



Fresh 



55 55 



25 



Lower 



1-73 



Fresh 



• J» >> • 



In air 





53-33 



Flaccid 



Prumis Laurocerasus 



0 



Upper 



13-72 



Fresh 



»» >» • 



20 



Lower 



4-51 



Fresh 



i» . >» • 



In air 





21-39 



Fresh 



Au cuba japonica 



0 



Upper 



5-97 



Fresh 



>> »» 



50 



Lower 



9-82 



Fresh 



»» >> 



In air 





27-84 



Slightly puckered 



Heeler a Helix . 



o 



Upper 



10-82 



Fresh 





45 



Lower 



16-64 (gain) 



Fresh 





In air 





10-26 



Fresh 



These specimens illustrate the fact that, unless the difference be very 

 pronounced, the eye cannot judge the amount of water a coriaceous, and 

 even not always a herbaceous, leaf may have lost ; secondly, that the loss 

 is not entirely dependent upon, or proportional to, the relative number of 

 stomata on the surface. In some cases, certainly the more often, there is 

 less loss when the lower side is on the water ; but even then this may not 

 be referable to the stomata more than to a less cuticularised condition of 

 the surface. 



In the next series, in each case one specimen was partly plunged in 

 water, the cut end (as in every experiment), as well as some leaves, were 

 elevated in the air. They remained thus from July 30 to August 3. 

 They were all weighed before and after the experiment, as before, in 

 grammes to three places of decimals. 







Loss 



Apparent 







per Cent. 



Condition 



Cedrus Deodara . 



Partly in water 



•09 



Fresh 



■ » >> • 



In air 



•57 



Dry and deciduous 



Hedera Helix 



2 leaves in water, 4 in air 



10-28 



Fresh 





In air 



10-26 



Fresh 



Syringa vulgaris . 



55 55 • 



4 leaves in water, 6 in air 



311 



Fresh 



In air 



67-20 



Dead and crisp 



Thuja, sp. 



,, ... 



Partly in water 



6-19 



Fresh 



In air 



21-97 



Fresh 



Taxus baccata 



Partly in water 



4-52 



Fresh 



>» >> • • 



In air 



23-92 



Fresh 



Ilex aguifolia 



Partly in water 



1-84 



Fresh 



55 55 • 



In aii- 



13-33 



Fresh 



These examples, and many others, show clearly that the leaves in air 

 on the branches which have other leaves in water are easily and well 

 nourished by the latter. In the case of ivy but little difference is seen 

 between the two percentages. This is due to the fact that, the transpiring 

 surface of four leaves being greater than that of the absorbing, the supply 

 was not equal to the demand. 



