Jay 



THE TROPICAL AGKICtJLTtJRlST. [Octobek r, 1885, 



though independently affixed to the rock, being under- 

 laid by a network of some vegetable fibrous substance 

 placed on the ledges (the Urococcus above-mentioned), 

 which the gatherers are careful not to remove. It 

 is generally supposed that these edible nests are made 

 by only one species of swift, Collocalia nidifica; but 

 Blyth determiiied the birds which Oapt. Lewis found 

 making Hmilar nests in the Nicobar Islands to be 

 OoUocalia fuciphaga, remarking that the natives who 

 gather the nests are much given to mislead inquirers 

 who interrogate them on the subject, which may 

 account for the erroneously published statements that 

 Collocalia fucijjhaga does not propnce an edible nest. 

 —Field. 



THE PITCHER PLANT. 



TO THE EDITOR OF " NATCEE," 



The variety of the Pitcher Plant {Samicenia variol' 

 a}'i:i) found in North America is carnivorous, being a 

 feeder on various animal substances. Mrs. Mary Treat, 

 an American naturalist, made a few years ago several 

 experiments upon the plants of this species to be 

 found in Florida; and to the labours of this lady the 

 wiiter has been indebted, in some measure, in the 

 preparation of this paper. The iSrirrncenia derives its 

 name of "Pitcher Plant" from the fact of its poss- 

 es-ing the following curious characteristics. The medi- 

 an never is prolonged beyond the leaves in the manner 

 ot a tendrd, and terminates in a species of cup or 

 urn. This cup is ordinarly three or four inches iu 

 depth, and one to one and a half inches in width. 

 The oritice of the cup is covered with a lid, which 

 opens and shuts at certain periods. At sunrise the 

 cup is found filled with sweet, limpid water, at which 

 time the lid is down. In the course of the day the 

 lid opens, when nearly half the water is evaporated ; 

 but during the night this loss is made up, and the 

 next morning the cup is again quite full, and the lid 

 is shut. About the middle of Jlarcli the plants put 

 forth their leaves, which are from six to tivelve inches 

 long, hollow, and shaped something like a trumpet, 

 whilst the aperture at the apex is formed almost pre- 

 cisely iu the same manner as those of the plants pre- 

 viously described. A broad wing extends along one 

 side of the leaf, from the base to the opening at the 

 top ; this wing is bound, or edged with a purple cord, 

 which extends likewise around the cup. The cord 

 secretes a sweet fluid, and not only flying insects, but 

 these also that crawl upon the ground, are attracted 

 by it to the plants. AJits, especially, are very fond 

 of this fluid, so that a line of aphides, extending 

 from the base to the summit of a leaf, may frequently 

 be observed slowly advancing towards the orifice ot 

 the cup, down which they disappear, never to return. 

 Flying insects of every kind are equally drawn to the 

 plant; and directly they taste the fluid they act very 

 curiously. After feeding upon the secretions for two 

 or three minutes they become quite stupid, unsteady 

 on their feet, and whilst trying to pass their legs 

 over their wings to clear them, thsy fall down. It 

 is of DO use to liberate any of the smaller insects, 

 every fly, removed from the leaf u^jou which it had 

 been feeding, retured immediately it was at liberty 

 to do so, and walked down the fatal cup as though 

 drawn to It by a, species of irresiatible fascination, 

 It is not alone that flies and other small iuBocts are 

 overpowered by the fluid which exudes from the cord 

 In question, Eveu large iusects succumb to it, although 

 of eourse not so quickly. Mrs. Treat says:— •• A large 

 cockroacb was feeding on the secretion ot a fresh leaf, 

 Which had CHUght but little or no prey. After feed- 

 ing a short tiiue the insect went down the tube so 

 tight tliat I could not dislodge it, evtn when turning 

 tbe leaf upside down and knocking it quite bard. It 

 wai late iu the evening when I observed it enter; 

 the next morning I cut the tube open; the cockroach 

 was etili alive, but it was covered with a secretion 

 produced from the inner aarface of the tube, and its 

 feg< fnli off as I extricated it. From all appoarance 

 he terrible Haryaccnia was eating its victim alive, 



^tid /et, p«rl>ajp«, I tbould not mjt ' teriiblt/ for (be 



plant seems to supply its victims with a Lethe-like 

 draught before devouring them." 



It only afew insects aliyht upon a leaf no unplea- 

 sant smell is preceptible during, or after, the process 

 of digestion ; but if a large number of them be caught, 

 which is commonly the case, a most offensive odour 

 emanates from the cup, although the putrid matter 

 does not appear to injure iu any manner the inner 

 surface of the tube, food, even in this condition, 

 being readily absorbed, and going to nourish the plant. 

 In tact, it would seem tliat the Srrracenia, like some 

 animals, can teed upon carrion and thrive upon it. 



In instances iu which experiments have been made 

 with fresh, raw beef or mutton, the meat has been 

 covered in a few hours with the secretions of the 

 leaves, and the blood extracted from it. There is, 

 however, one difference between the digesting powers 

 of the leaves when exercised upon insects or upon 

 meat. Even if the bodies of insects have become putrid 

 the plant, as has already been stated, has no difticulty 

 in assimilating them ; but as regards meat, it is only 

 when it is perfectly sweet that the secretion of the 

 leaves will act upon it. 



The Pitcher plant undoubtedly derives its principal 

 nourishment from the insects it eats. It, too — unlike 

 most other carnivorous plants, which, when the quant- 

 ity of food with which they have to deal is in excess 

 ot their powers of digestion, succumb to the effort and 

 die — appears to find it easy to devour my number of 

 insects, small or large, the operation being with it 

 .simply a question of time. Flies, beetles, or even 

 cockroaches, at the expiration of three or four days 

 at most, disappear, nothing being left of them save 

 their wings and other hard parts of their bodies. 



The Sorraccnia is, indeed, not only the most voraci- 

 ous of all known species of carnivorous plants, but 

 the least fastidious as to the nature of the food upon 

 which it feeds. "W. 0. M. 



Perhaps you will allow me to set "W. 0. M." 

 right with regard to Sarracenia va-j iolaris and pitcher 

 plants generally. I am afraid the sources from whenee 

 he obtained his information were not very j.ehable, 

 as will be seen from the following: — 



There are six species of Sarracenia found in North 

 America, all of them characterised by the same tr uinpet- 

 shaped leaves growing in tufts, and in several ot the 

 species attaining a length ot a yard. In addition to 

 these there is the Dar/iuytonia californica, which has 

 long twisted trumpet-shaped leaves, the top ot which 

 is curved over, forming a sort ot hood, and having a 

 rather small aperture on each side. These constitute 

 the whole of the pitcher pl.ants ot North America. 

 " W. 0. JM.," whilst professing to describe the " curi- 

 ous characteristics" of the Sarracenia, really describes 

 the leaf and pitcher of Nepenthes, which, as almost 

 evrybody knows, are tropical plants, mostly natives 

 of the Indian Archipelago, and well known in this 

 country as ornamental stove plants. The pitchers vary 

 much in size, some of the species producing them 

 quite eighteen inches long and capable of holding a 

 quart of water, whilst others have pitchers no larger 

 than a thimble. "W. 0. M." is quite wrong in say- 

 irg that the lids of the pitchers of Nepenthes, or 

 indeed of any pitcher-plant known, close again after 

 they have once opened. When the pitcher is about 

 full-grown, the lid pushes open, widely in some species, 

 only slightly in others, and remains quite stationary 

 till the pitcher dies. When the lid opens, the pitcher 

 is found to be about one-quarter filled with a sweetish 

 watery liquid, L'^uder cultivation it is necesisary to 

 keep the pitchers filled with water, or they soon 

 shrivel) and it is found that, however frequently the 

 water is renewed, it soon acquires a slight sweetness j 

 60 that the secretion of " honey " going on in the 

 pitcher must be somewhat copious. If the water which 

 19 iu the pitcher when it first opens dries up, there 

 is no further secretion of liquid — at least such is the 

 case with cultivated plants. At Kew the oldest pitch- 

 ers on the Nepenthes attract insects as long as they 

 ciintnin moisture. The Sarracenias have their pitchers 

 formed by tbe folding and joiaiDi; of tbe odgu of tb$ 



