102 



BOTANY. 



however, by making a large number of very thin sections of the whole 

 leaf (by placing it between two pieces of elder pith), when it will be 

 found that in some cases stomata have been cut through in the man- 

 ner shown in Fig. 92. 



(b) Examples may be obtained from any of the higher plants, but 

 those which are of a firm texture and have a smooth epidermis are 

 best to begin with e.g., the hyacinth, tulip, the lilies, many grasses, 

 fuchsia, lilac, etc. 



(c) Weiss* determined the number of stomata on the epidermis of 

 both surfaces of 167 leaves of plants ; some of his results are given 

 below : 



[n one square millimetre. 



Upper Bide. Tinder side 



Olea Europea 



Vinca minor . , 



Juglans nigra 



Ailanthus glandulosa 



Syringa vulgaris 



Helianthus annuus 175 



Brassica oleracea 138 



Platan us occidentals 



Populus dilatata 55 



Solan um dulcamara 60 



Euphorbia cyparissias 



Maclura aurantiaca 



Betula alba 



Berberis vulgaris 



Pisum sativum 101 



Buxus sempervirens. 



Prunus Mahaleb 



Asclepias incarnata 67 



Datura stramonium 114 



Taxus baccata 



Zea mais 94 



Chenopodium ambrosioides.. 184 



Ficus elastica 



Ribes aureum 



Populus monilifera 89 



Pinus sylvestris 50 



Anemone nemorosa 



Lilium bulbiferum 



Iris Germanica 65 



A vena sativa 48 



625 

 477 

 461 

 386 

 35*0 

 325 

 302 

 278 

 270 

 263 

 259 

 251 

 237 

 229 

 216 

 208 

 204 

 191 

 189 

 166 

 158 

 156 

 145 

 145 

 131 

 71 

 67 

 62 

 58 

 27 



In one square inch. 



Upper side. : Under side, 





 

 

 

 



112,875 



88,910 







35,475 

 38,700 

 

 

 

 



65,145 

 

 



43,215 



73,530 







60,630 



118,680 











57,405 



32,250 











41,925 

 30,960 



403,125 



308,665 



298,345 



248,970 



212,850 



209,625 



194,790 



179,310 



174,150 



169,635 



167,055 



161,895 



152,865 



147.705 



139,320 



134,160 



131,580 



123,195 



121,905 



107,070 



101,910 



100,620 



93,525 



93,525 



84,495 



45,895 



43,215 



39,990 



38,410 



17,415 



*In a paper on the Number and Size of Stomata, published in 

 Pringsheim's " Jahrbilcher fur Wissenschaftliche Botanik," 1865. 



