53 



CELLULAR TISSUE. 



Hieracium sabaudum, Eupatorium verticillatum, Platanus occidentalis, Corylus Avellana, 

 Claytonia linoides, Escallonia spec, Aralia racemosa, Ferula tingitana. A numerous group 

 of pores is to be found at like points in Tommasinia verticillaris, Archangelica officinalis, 

 Smyrnium perfoliatum, Heracleum flavescens, Eryngium planum, and other Urabelli- 

 ferae ; Cerastium glabratum, Geum agrimonioides, Aremonia, Fotentilla Thuringiaca, and 



Fig. 19.— Tropjeoluin Lobbianum; upper surface of leaf. .^ /i<al enirlormic f..««, n, 

 the end of a strong vascular bundk, with three large wate^oS-Ja^-ZreS cVl^'^A- T 

 section through water-pores and their immediate vicinity (4rt In C some oTihe ceUs"^ » ™ h" 

 the wide respiratory cavity have grown outmto large papillfrising LoThe cavUy '"^--i-ng 



other species; Alchemilla vulgaris, Ranunculus lanuginosus, and other species- Physos- 

 tegia virginica, Lycopus exaltatus, Hieracium Pilosella, denticulatum (apex 'of leaf), 

 Rudbeckia speciosa, Senecio vulgaris, and other Composite; Valeriana Phu., Brassica 

 spec, &c. In the examples given, the upper side of the leaf has air-pores also. Galium 



