Prof. Ch. Morren on the Morphology of the Ascidia. 311 



its surface inwardly covered with those glands, so well de- 

 scribed by M. Meyen in his excellent memoir on the glandu- 

 lar system of vegetables*, glands which, according to the ob- 

 servations of Turner, secrete a liquid, which by ebulHtion ac- 

 quires a smell of baked apples and deposits crystals of the 

 super-oxalate of potash f. These glands evidently represent 

 the ovules of the carpels, the pollen of the anther, the necta- 

 riform fluid of the ascidimorphous bracts of Norantea and of 

 Marcgravia, that is to say in one word, the secretions of the 

 upper surface of the leaf, the typical organ. Upon the oper- 

 culum of the pitcher in Nepenthes cristata, on that surface 

 which faces the cavity of the pitcher, there are similar glands. 

 Now this is the upper surface of the leaflet which constitutes 

 the operculum. 



The outer surface of the pitcher is then in our opinion the 

 under part of the leaf which has formed the ascidium. We 

 also find upon it the stomata which abound on the corre- 

 sponding surface of the leaves. Upon Nepenthes distillatoria 

 the lower surface of the winged petiole offers the same dull 

 aspect as the outer surface of the urn, and within this, upon 

 a dry specimen, gathered in the Edinburgh Botanic Garden, 

 I perceive in the zone above the glandular region a waxy 

 velvet, of a varying violet colour, like the bloom which covers 

 grapes and plums, globules of wax which hinder the urn from 

 becoming wet within, and which moreover, favouring my sy- 

 stem, indicate the existence of a glandular excretion. 



In the same manner, upon the ascidium of Polygonatum the 

 inner surface was covered with a gum, like the upper surface 

 of the leaves of this plant, and its outer superficies dull like 

 the under surface of the leaves. 



Lastly I will add, that upon Nepenthes cristata the crests 

 which imitate the two margins of the ascidimorphous leaf are 

 pectinated with flattened and stiff* hairs, like the blade of Dio- 

 ncea muscipula. 



If we look at the ascidia of Sarracenia we see nothing which 

 authorizes us to take them for petioles. Upon Sarracenia 



♦ Berlin, 4to, 1837, i%88. tab. v. fig. 11—27. 

 t Graham, Botanical Magazine, 2798. 



