398 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY 



force is necessary to do this. The first thing observable is that 

 the piece of egg is bathed with a secretion which colours litmus- 

 paper red when touched. In a day or two more the corners of 

 the cube will be found to be rounded, and this process goes on 

 until the piece of egg is dissolved. This may take a fortnight or 

 three weeks' time to accomplish, according to the amount given. 

 The secretion is absorbed by glands in the interior of the leaf. 

 It does not pass down the leaf-stalk to the root, because litmus- 

 paper tied round the leaf-stalk shows no reaction. 



The order Nepentliacece, is limited to the single genus Ne- 

 penthes, or " Pitcher-plant," which consists of about forty 

 species and a large number of hybrid varieties. They are 

 shrubby, climbing, and dioecious plants. The pitcher of 

 Nepenthes, which is its most striking feature, is an appendage 

 of the leaf, developed at its apex, and is furnished with a stalk, 

 often a very long one. This stalk, in the case of pitchers 

 formed high up on the stem, has the power of twisting like a 

 tendril round neighbouring objects, and thus the plant climbs 

 to a great height in the forests. In most species the pitchers 

 are of two forms — one appertaining to the young state of the 

 plant, when they are short and inflated ; the other belonging to 

 the old state, when they are longer and more funnel-shaped. 

 The mouth of the pitcher is furnished with a thickened corru- 

 gated rim, which serves three purposes : first, it strengthens the 

 mouth, and keeps it distended ; second, it secretes honey ; and 

 third, it forms a row of teeth, which descend into the pitcher and 

 prevent the escape of insects. In some species this row of teeth 

 is strong enough to retain small birds, should they thrust their 

 body beyond a certain length in search of insects. The pitchers 

 are often highly coloured, and vary in size from an inch or two 

 to a foot or eighteen inches in length in the different species. 

 They invariably contain a fluid. 



The minute structure of the interior of the pitcher is of a 

 very complicated nature. It presents three distinct surfaces. 

 The first is the " attractive " surface, which occupies the inside 

 of the lid and the mouth of the pitcher. The inside of the lid is 

 studded over with honey- secreting glands, which are also 

 present round the corrugated rim. The glands consist of 

 masses of cells embedded in depressions of the cellular tissue 

 of the lid, and each is surrounded by a ring of guard-cells. 



