368 



NA TURE 



[February 17, 1898 



first place the fluid is absolutely unpotable ; and secondly, 

 nearly all the known species of Nepenthes grow in 

 climates where the traveller need never be thirsty. Mr. 

 Burbidge states that on the great mountain range of 

 Kina Balou, in North-west Borneo, the "paradise of 

 pitcher-plants," there is a deluge of rain every night in 

 the year, while in the day-time the air is in a constant 

 state of " Scotch mist." The internal surface of the 

 pitcher is provided with a large number of specialised 

 glands, from which the secretion is poured out into the 

 pitcher. The fluid has a slightly acid reaction, and 

 yields a large quantity of solid matter on evaporation ; 

 and the most trustworthy analyses that have been made 

 show that the preponderating unorganised constituents 

 are potassium chloride and malic and citric acids, with 

 smaller quantities of soda, lime, and magnesia. The 

 researches of Vines have convinced him that the pitcher 

 secretes an enzyme which has the property of digesting 

 organic substances in the presence of an acid which is 

 always found in the fluid ; and that this digestion is not 

 due to the putrefactive bacteria which are always present 

 in the liquid. All the species of Nepenthes are either 



Fig. 2. — Pitcher of Nepenthes Dicksoniana, one-fourth natural size. 



epiphytic or grow in wet soil, and agree with other 

 carnivorous plants, such as Drosera and Dtoncea, in 

 having a very reduced root-system ; the food-substances 

 obtained through the pitchers thus supplying the lack of 

 nutriment from the soil. 



None of the other pitcher-plants, with the possible 

 exception of Cephalotus, are, according to Vines, truly 

 carnivorous. In most cases they are insect-traps, but 

 they produce no digestive enzyme ; the captured insects 

 are decomposed by the microbes which abound in the 

 fluid, and the products of decomposition absorbed by the 

 plant. In Darlingtonia, and in Sarracenia, one species 

 of which, the "Side-saddle-plant," is abundant in bogs in 

 the Northern United States and in Canada, the lid is 

 replaced by a hood, and insects are attracted by honey- 

 glands placed near the mouth of the pitcher. In Dischidia 

 the pitcher, which has no lid, is not nutritive ; its main 

 use appears to be to husband the water required by the 

 plant. The pitchers of Cephalotus closely resemble in 

 appearance those of Nepenthes. Several species of Utri- 



NO. i477r VOL. 57] 



cularia, or Bladder-wort, are among the prettiest of our 

 water-plants, with their pale yellow flowers and much- 

 divided leaves, ornamented with the minute bladders, 

 which are closed by a valve opening inwards, thus pre- 

 venting the escape of innumerable aquatic animals which 

 creep into them. It may be added in conclusion that 

 one of our few native non-chlorophyllous root-parasites, 

 the Tooth-wort {Lathrcea squamaria), belonging to the 

 Scrophulariaceae, has singular hollow underground scale- 

 leaves, which may be regarded as rudimentary pitchers, 

 and resemble those on the exotic terrestrial species of 

 Utricularia. Their purpose appears to be the reverse 

 one to that of the pitchers of Dischidia., viz. to serve as 

 organs for the excretion of superfluous moisture. 



Our illustrations are taken from Mr. Veitch's paper on 

 Nepenthes in the Journal of the Royal Horticultural 

 Society. Fig. i, a hybrid known as N. Sedenii., a cross 



Fig. 3. — Nepenthes Edwardsiana, 



between N. Khasiana and an unknown species, shows 

 the general habit of the genus. Fig. 2 represents the 

 magnificent pitcher of A''. Dicksoniana, a cross between N. 

 Rafflesiana and N. Veitchii. In Fig. 3, N. Edwardsiana, 

 Hook, f., a spike of male flowers is shown ; also a 

 magnified portion of the glanduliferous surface of the 

 pitcher. A. W. B. 



A NEW ARTILLER V CHRONOGRAPH} 



THE ordinary chronograph used in artillery experi- 

 ments consists of a falling shutter held suspended 

 by an electromagnet whose circuit is broken by the pro- 

 jectile, which cuts a wire in its passage. Other wires are 



1 Based upon an article in La Nature, pp. 97 and 122, 1898. 



