LUCCLIA. 



LUMINOSITY OF ORGANIC BEINGS. 



polished, anterior elongated. The animal has the mantle margin* 

 nearly plain, united; pedal opening large, ventral; foot pointed, 

 hallow ; palpi large, free ; gilli 2 on each aide, distinct, the outer 

 oral, inner broadest in front, united behind ; branchial orifice small, 

 imple ; anal larger, with a plain valve. 1). nlumlala is found in the 

 British sees. There are IS recent specie* found in the West Indie*. 

 the Mediterranean, Red Sea, India, Australia, and America. Fossil 

 ipecie* have also been found in the tertiaries. 



(Forbes and Hanley, llutory of ISriluh Moiltuca; Woodward, 

 RmKmnlary TrnHite on Krtent and Fouil SMU.) 



LUCU'LLA, a genus of Plants belonging to the natural order 

 CitdumtKftr, tribe Oittdumeat, and sub-tribe Kucinchoneit ; thus indi- 

 cating the close affinity of this genus to that of the trees yielding 

 Peruvian Bark, or true Cinchonas, in which indeed the only known 

 species, L. yratiuima, was plaoed by Dr. Wallich and figured in his 

 1 Tent. FL Nepal,' t 21. 



It is found in great abundance on Nag-Urjoon and some of the other 

 smaller hills in the valley of Nepaul ; also at Bechiaco and Koolakan. It 

 delights in exposed rather naked situations, blossoming, according 

 to the situations where it is found, nearly the whole year round. It 

 is also found on the Pandooa Hills in Silbet, flowering in the month 

 of September. As seen by Dr. Wallich it attains a height of 16 feet, 

 but he was informed of its growing to a larger size. It has been 

 introduced into and has flowered in this country ; but from the 

 nature of the climate where it is indigenous, it is only suited to the 

 greenhouses of England. Its locality and affinity are interesting, 

 particularly when coupled with the prevalence in the same mountains 

 of two other genera, llymenwlictyon and Jfymenojtogon, belonging to 

 the same sub-tribe Eudnckonea, and therefore equally allied to the 

 true Cinchonas ; all indicating the part of the Indian territory where 

 these valuable plants might most certainly be grown, and yield a pro- 

 fitable article of commerce. " It is impossible to conceive anything 

 more beautiful than this tree when covered with its numerous rounded 

 panicles of pink-coloured very fragrant large blossoms." (Wallich, 

 La, p. 30.) 



LU'CUMA (a native name for one of the species), a genus of Plants 

 belonging to the natural order Sapotactte. It has a 5-parted calyx ; 

 a 5-cleft corolla ; 10 stamens, 5 of which are sterile and 5 fertile, alter- 

 nating with each other ; an ovarium 5-10-celled ; the fruit 1-10-seeded; 

 nuts or seeds bony, marked by a large umbilical areola without albumen. 

 The species are trees, yielding a milky juice, with scattered entire 

 coriaceous leaves, and 1 -flowered axillary or lateral peduncles. 



L. Mammota, the Common or Mammee Sapota, has obovate-lanceo- 

 late oblong-cuspidate glabrous leaves, with solitary flowers. This 

 plant grow* from 50 to 100 feet in height. It is a native of the tropical 

 parts of South America, and of many of the West India Islands, 

 where it is also cultivated. The fruit of this tree is eaten in the 

 West Indies. It is of a large size, oval-shaped, and covered with a 

 brownish rough akin, under which is a soft pulp of a russet colour, 

 very luscious, and which, on account of its flavour, is called Natural 

 Marmalade. P. Browne calls a variety of this tree Bully-Tree, because 

 it grows the tallest of all the trees in the woods of Jamaica. 



Several other species of this genus have been described. They are 

 all natives of various districts of South America, and yield edible 

 fruiU similar to the preceding species. They were at one time referred to 

 the genus Achrat, the species of which also yield edible fruits, f ACIIKAS.] 



(Don, Diddamydanu J'la*tt.) 



LUDLOW ROCKS. The upper part of the Silurian System of 

 Sir Roderick Murchison is thus designated. They include the three 

 following terms : 



Upper Ludlow Rock, a thick mass of laminated arenaceous deposit*, 

 seldom acquiring considerable hardness, and suggesting the notion of 

 having bean deposited as a muddy sediment ; from which circumstance 

 it has also been called Mudstone by Sir 11. Murohuon. It is very rich 

 in fossili 



Aymestry Limestone, a concretionary and polypiferous limestone, 

 of local occurrence and small thicknots, merely separating the other 

 terms. Many fossils. 



Lower Ludlow Rock, chiefly an argillaceous, shaly, and flaggy 

 deposit, with a few calcareous nodules, yielding shell.-. 



The Limestone of Wcnlock and Dudley lies below. [SiLuniA.x 



I.I 'KFA, a genus of Plant* belonging to the natural order Cucurii- 

 tacta. The male flowers are panicled and yellow ; the tube of the 

 calyx hemispherical, segments longer than tlie tube ; petals distinct, 

 dropping off by the base; stamens 6, distinct; anthers very wavy. 

 The female flowers are solitary ; the tube of the calyx oblong, cUvatc, 

 eg mills shorter than the tube ; stamens abortive ; stigmas reniform ; 

 gourd ovate, 8-cellcd, fibrous, internally opcrculate. 



L. amara is found in hedges and dry uncultivated places in the 

 East Indies. It has several stems, slender, running to a great extent, 

 but with few tranche*, pretty smooth, 6-sided ; tendrils 3 cleft ; leaves 

 lightly 5 7-lobcd, rough ; stipules axillary, solitary, cordate, with 

 glandular marks on one side. Male flowers pretty largo, yellow, on 

 long erect axillary racemes ; the pedicels with a glandular bract near 

 the base, and articulated a little abuve it Female flowers rather 

 larger, axillary, solitary, pedunculated ; fruit oblong, 3 or 4 inches 

 long, and 1 inch in diameter, tapering equally towards each end, 



10 angled ; when ripe dry, gray, and filled with dry fibres; the :' 

 culum deciduous; seeds blackish-gray, with elevated minute black 

 dots ; every part is extremely bitter. The fruit is violently cathartic 

 and emetic ; the juice of the roasted young fruit is applied to the 

 temples to cure headache by the natives of India; the ripe seeds are 

 used either in infusion or substance by them to vomit and purge. 



L. Bindaal is a native of Hindustan. It is a climbing dioecious 

 plant ; the leaves are tojthed and 5-angled. Male flowers in racemes. 

 Female flowers solitary ; fruit round, echiuate, with long, straight, 

 ciliate bristles. It it considered in northern India a powerful drastic 

 ill cases of dropsy. The leaves of L. aculanyula are a favourite 

 potherb of the natives of India, aud nre esteemed very wholesome. 



LUG-WORM. [ABE.MCOLA.] 



LUIDIA. (KOHIXUUEHMATA.I 



LUMACHELLE. [MARBLE.] 



LUMBRICARIA, a genus of fossil Annelida, from the Silurian 

 Strata of Tyrone. ( Portlock.) 



LUMBRICUS. [ANNELIDA.] 



LUMINOSITY OF ORGANIC BEINGS. Organic bodies under 

 certain circumstances become luminous, and upon the supposition 

 that this appearance depends on the combustion of phosphorus at a 

 low temperature, the phenomenon has been called phosphorescence. 

 This luminosity is very constantly developed under the same circum- 

 stances in both animals aud plants. It is observed both during the 

 decomposition of the bodies of plants and animals as well as whilst 

 they are still living. The oldest observations on this subject were 

 made on the wood of trees whilst in a state of decay. This however 

 takes place only under peculiar circumstances. It generally occurs 

 when the wood of trees is buried in the earth whilst they are in a 

 green state, and does not take place when wood is allowed to decompose 

 in the usual way and in free contact with the air. It is also found 

 that the phosphorescence does not take place when the wood is 

 allowed to decompose in a damp place. Wood exhibiting this property 

 will retain it for a long period when kept in a dry place. Albrecht 

 observed luminosity in a tree during the night at a spot where one of 

 its branches had been toru off. Decaying fungi have been often 

 observed to emit this light Travellers in tropical climates have 

 observed that when plants containing a milky juice are wounded, the 

 juice frequently becomes luminous, whilst it is descending the sides 

 of the tree. The cause of this phenomenon in decaying plants in 

 probably owing to a alow decomposition of the tissues attended with 

 a union of oxygen gas, but what determines the development of light 

 under these more than other circumstances is still unknown. 



In living plants luminosity has been frequently observed. It is 

 most constant amongst some forms of fungi, especially of the genus 

 Rhiiomorpha. In the coal-mines in the vicinity of Dresden the species 

 of Jihizumorjihcc are so numerous as to " dazzle the eye by the brilliant 

 light they afford." [BYSSACE.K.] The light from decaying wood, as 

 also from the living Rhisomorpha, continues although they are 

 immersed in irrespirable gases, linseed oil, phosphoric acid gas, oxygen, 

 &c. The phenomenon in both the living and the dead plants in 

 probably due to the same cause. 



Another class of plants in which light has been observed is the 

 Mosses. Several species of the genus Schutottcya, which grow in 

 caverns and other damp places, have been observed to give out light 

 Mr. Babington and other botanists have observed it in this country 

 in the S. pennata ; whilst Funk, Brandenburg, Nees von Eseubeck, 

 Homschuchc, Struve, Unger, Bridel-Briderei, and Agardh, have 

 observed it on the continent of Europe. The two latter attributed 

 this light to a small- alga, which Bridel-Briderei called C'aloptridium 

 tmaragdinum, and Agardh called Protococcui tmaragdintu, which they 

 supposed was parasitic on the moss. Unger however has examined 

 the moss accurately, and finds that at certain seasons the utricles of 

 this moss assume a globular form, and being partly transparent, the 

 light is refracted and reflected in such a way as to present a luminosity 

 on the surface of the vesicles. 



Another class of these phenomena is that which is exhibited by tin; 

 flowers of some plants. The first observation on this subject was 

 recorded by Liumuus, and made by his daughter Christina Liunc. 

 She was walking in the garden one hot summer's evening, when she 

 observed the flower* of Tropaolum majut to give forth a stream of 

 light This was attributed by many to an optical illusion, but the 

 fact has since been repeatedly observed on this as well as other plants. 

 We are not perhaps in a ]>osition to say this was not an optical 

 illusion; but if it was, one would expect that it should be more 

 constant It has also been seen by several observers at the same 

 time in different positions, and when one has seen it, the others have 

 seen it also. A correspondent of the 'Gardener's Chronicle,' Oct, 

 1843, says, " I have frequently observed the luminous appearance of 

 garden plant*, and have looked for it in each succeeding summer on 

 the double morygold, and more especially on the Paparer }>iloium, the 

 hairy red poppy, in my garden at Worcestershire. In the evening 

 after a hot dry day, the flashes of light have afforded much amuse- 

 ment to myself and others." It is to this phenomenon that Coleridge 

 alludes in the following lines : 



" Tis (aid on rummer's evening hour 

 Fluhei the goldcn-colour'd flower 

 A fair electric flame." 



