| OCR Text |
Show In the Apocynum Androfremifolium, one kind of Dog's-bane, the anthers converge over the nechrics, which conflfl of fi ve gbndular oval corpufcles furrounding the germ; and at the fame time admit air to the neB-a ries at the intcrllice between each anther. But when a fly inferts its wobofcis between thefe anthers to plunder th<.! honey, they converge clofer, and with fuch violence as to detain the fly, whi ch thus gc nendly perifl1es. This account was related to me by R. W. Darwin, Efq. of Ell1on, in Nottinghamfhire, who f11ewed me the plant in flo v1:er, July 2d, 1788 , with a fly thus held fafl by the end of its probofci s, and was well feen by a magnify ing lens, and which in vain repeatedly firuggled to difengage itfelf, till the converging anthers were [eparated by means of a pin: on fome days he had obferved that a! molt every flower of this elegant plant had a fly in it thus entangled; and a few weeks afterwards f:.tvoured me with his further obfervations on this fubject. " My Apocynum is not yet out of flower. I have often vifi tcd it, and h:~ve frc- " quc ntly·found four or five fli es, fome alive, and fomc dead, in its flowers ; they are generally caught by the trunk or probofcis, fomctimcs by the trunk and a leg; there is one at prefent only caught by a leg : I don't know that this plant fl ecps, as the fl owers remain open in the night; yet the fli es frequ ently make their efcape. In a pla nt of Mr. Ordoyno'•:, an ingenious gardener at Newark, who is poffdfed of a great colleCl.ion of plants, I faw many flowers of an Apocynum with three dead flies in each; they are a thin -bodied fly, and rather lefs than the common houfe-fly; but I have " feen two or Lhree other forts of fl ies thus arrefl:ed by the plant. Aug. I2, 1788." P. I 8. Adt!itional note on f lex. The efficient caufe, which renders the hollies prickly in Needwood ForeH only as high as the animals can reach them, may arife from the lower branches being confl:a ntly cropped by them, and thus !hoot forth more luxuriant foli:1ge: it is probable the fh ea rs in garden-hollies may produce the fame effect, which is equally curious, as pricklc;s are not thus produced on other plant-s. P. 41. Additional note on Ulva. 1\1. H ubert made fome obfervations on the air contained in the cavities of the bambou. T he fl:ems of thcfe ca nes were from 40 to 50 feet in h<.ight, and 4 or 5 inches in diameter, and might conta in about 30 pints of elafl:ic air. He cut a bambou, and introduced a lighted candle into the cavity, which was extinguiilied immediately on its entrance. He tried this about 6o times in a cavity of the bambou, containing about two pints. He introduced mice at di ffe rent times into thefe cavities, which feemed to be fomcwhat affected, but foon recovered their agility. The fl:cm of the bambou is not hollow till it rifes more t h:~n one foot from th~ eart h ; the divifions between the cavities arc convex downwards. Obferv. fur la Physique, par M. Rozier, I. 33, p. I 30. P. 136. Additim to the note on Tropceolum. In Sweden a \'cry curious phenomenon 'has been obferved on certain flowers, ·by M. Haggren, Lect urer in Natural Hifl.ory. One evening he perceived a faint flalh of light repeatedly dart from a Marigold ; fur~ prized at fuch an uncommon appearance, he refol ved to examine it with attention ; and, r 185 J to be affurecl that it was no deception of the eye, he placed a man ncar him, with orders to make a flgnal at the moment when he obfervcd the light. They both faw it confl:antly at the fame moment. The light was mofl: brilliant on Marigolds, of an orange or flame colour; but fcarcely vifible on pale ones. The flailt was frequ ently feen on the fame flower two or three times in quick fucceffion, but more commonly at intervals of fcvcral minutes; and when feveral fl owers itt the fame pl ace emitted their light together, it could be obfervcd at a confiderablc diCI:ance. This phrenomenon was remarked in the months of July and Augufl:, at fun.fet, and for half an hour after, when the atmofphere was clear; but after a rainy day, or when the air was loaded with vapours, nothing of it was feen. The following flowers emitted flaOtes, more or lefs vivid, in this order: 1. The Marigold, ( Calendula qfficinalis) . 2. Garden Nafl:urtion, ( Tropceolum mnjus) . 3· Orange Lily, ( Lilium bulbiferum). 4· African Marigold. (Tagetes patula ct ere[faj . Sometimes it was alfo obferved on the Sun-nowers, ( H elianthus annuus) . But bright yellow, or flame colour, feemed in generalneceffary for the produCl.ion of this light; for it was never fcen on the flowers of any other colour. To di fc over whether fome little infeCl.s, or phofphoric worms, might not be the caufe of it, the flow ers were carefully examined even with a microfcopc, without any fu ch being found. From the rapidity of the fl a01, and other circumO:ances, it might be conjcCl.ured, that there .is fomcthing of electricity in this phrenomenon. It is well known, that when the pijlil of a flower is impregnated, the pollen bmfls away by its elaO:icity, with which eleelricity rnay be combined. But M. Haggren, after having obferved the flafh from the Orange-lily, the anthers of which are a confiderable fpace diftant from the petals, found that the light preceded from the petals only; whence he concludes, that this eleCtric light is ca11fecl by the pollen, which in fl ying off is fcattereclupon the petals. Obfer. Physique par M. Rozier, Vol. XXXIII. p. III. Difcription of the Poifon-Tree in the Ijland of J 1\ v /\. T"ranjlated from the original Dutch of N. P. Foerfch. THIS defl:ructivc tree is called in the Malayan language Bohun-Upas, and has been Jefcribed by naturalill:s ; but their accounts have been fo tinCl.ured. with the marvello:u, that the whole narration has been fuppofcd to be an ingenious ficbon by the general1ty of readers. Nor is this in the leafl: degree furprizing, when the circumll:ances which \ \'e {hall faithfully relate in this defcription arc confldercd. I mufl: acknowledge, that I long doubted the exificnce of this tree, until a firictcr <' nquiry con vinced me of my error. I fl1all now only relate fimple unadorned faCl.s, of B b |
