PISTACITE. 



PITTA, 



see 



style varies very much ; in some plants, as in Colchicum, it is 7 or 

 8 inches long, whilst in the NympTuzacea and Papaveracece it can 

 hardly be said to exist at all. The canal of the style was first dis- 

 covered by Malpighi. It is a continuation of the cavity of the ovary, 

 and terminates in the surface of the stigma. This canal varies in 

 extent in different places, in some being very narrow, and in others 

 very wide. It is lined with a peculiar kind of cellular tissue, having 

 a papillary character, and is covered with a viscous secretion. It is 

 called by Brongniart ' tissu conducteur," or conducting tissue, on account 

 of its supposed office in conducting the pollen tubes from the stigma 

 to the ovule. 



The style is often covered with hairs, which, on account of their 

 supposed office of clearing the pollen from the cells of the anthers, 

 have been called collectors. Sometimes these hairs are united together 

 into a kind of cup around the stigma, as in Goodeniacece, when they 

 form what is called an Indusium. 



The Stigma is composed of the same kind of tissue as the interior 

 of the canal of the style, but has a more spongy appearance. Its 

 papillary character also is more evident, and the little swellings on 

 its surface are often called papilla?. These papilla) become less evident [ 

 as the canal of the style approaches the ovary. The stigma assumes ; 

 a variety of forms, the distinction of which is often of importance in 

 systematic botany. These forms depend principally upon the tissue ' 

 of which its surface is composed. Sometimes the papillae are developed j 

 into little hairs, as is seen in the stigma of Urtica urens. In other ' 

 cases it is perfectly smooth, as in Nymphceaceas. In rhubarb it is ' 

 composed of three fat orbicular discs. In grasses it is in the form of [ 

 a tufted hairy body like a little brush. In Mimulug it has two lips 

 which have the power of contracting, and in Clarkia it consists of 

 four broad lobes. In Orchidaecce it has a structure in accordance j 

 with the anomalous character of all the parts of the flower in these 

 plants ; it consists of on oval humid space which occupies the middle 

 of the central column, and is covered with a thick viscous secretion. 

 In some cases however the stigma is not distinguishable from the 

 style, as in Asclepiat and Tupittra. 



The position of the stigma is sometimes anomalous. As it forms 

 the apex or point of the carpellary leaf, it ought always to be alter- 

 nate with the placenta!, which are formed at the margins of the leaf, 

 but in Cruciferce the stigmata are opposite the placenta;. This may 

 be explained in two ways. Dr. Lindley supposes that hi this order 

 there are originally four carpels, two of which being abortive, the 

 stigmata are left opposite the placenta;. Brown on the contrary sup- 

 poses that the stigmata are originally 2-lobed, and that the lobes have 

 united on each side, and thus obtained their abnormal position. 

 [SEED ; REPRODUCTION IN PLANTS.] 

 PISTACITE. [EPIDOTE.] 



PISUM, a genus of Plants belonging to the natural order Legu- 

 minosrr, and the tribe Vicieir. It has a calyx with foliaceous segments, 

 the two upper ones being shortest ; the vexillum ample, reflexed ; the 

 style compressed, carinated, villous above; the legume oblong, rather 

 compressed, but not winged; the seeds globose, numerous, with a 

 roundish hilum. 



P. tativum has two or many-flowered peduncles, with red or white 

 flowers, and is the common pea of our fields and gardens. 



P. arrente has 1-flowered peduncles and always red flowers, and 

 yields the gray peas of the fields. [PEAS, in Asia AND Sc. Div.] 



P. maritimum, the Sea-Pea, has an angled stem, the petiole flat- 

 tened on the upper side; the stipules broad, sub-sagittate; the 

 peduncles many-flowered, shorter than the leaves. This plant is a 

 native of France, Denmark, and other parts of Europe, and also of 

 Kamtchatka. In Great Britain it is found on the pebbly beach of 

 Lincolnshire, Sussex, Kent, and Suffolk. It is said to have been first 

 observed in Great Britain, at Orford in Suffolk, in the year 1555, when 

 during a great scarcity of food the poor people of that district were 

 almost entirely supported for acme time by its seeds. There is a 

 tradition that it sprung up after the wreck of a vessel loaded with 

 peas on the coast, but this could not be the case, as the Sea-Pea is a 

 very different species from any other. The seeds are bitter, and 

 cattle are fond of the herb. There are three or four other species of 

 pea, affording edible seeds, but not so valuable as the first. 



PISUM (Zoology), Megerls's name for a genus of Conchiferous 

 Mollvaca (Pindium, Leach), separated from Cyclai, 

 PITCHBLENDE. [UBASIUM.] 

 PITCHER-PLANTS. [LEAP; NEPENTHACEJE.] 

 PITCHSTONE, a Mineral occurring massive. Structure compact, 

 sometimes slaty, occasionally curved. Fracture imperfectly con- 

 choidal. Hardness 5'0 to G'O. Colour brown, black, gray, red, &c., 

 and variously mixed. It is generally dull, but has sometimes a resino- 

 vitreous lustre. Translucent. Opaque. Specific gravity 2'3 to 27. 

 It occurs at Meissen in Saxony, at Newry in Ireland, and in the island 

 of Arran, and other places. 

 Analysis of Irish Pitchstone by Knox : 



Silica 72-80 



Alumina 11-50 



Soda 2-85 



Lime 1'20 



Protoxide of Iron 3-03 



Water 8'50 



99-88 



PitchMone is also applied to a Siliceous Rock of igneous origin, 

 generally occurring in dykes which traverse the strata, or in overlying 

 columnar masses. Among recent volcanic rooks its analogue is 

 Obsidian. M'Culloch gives the characters of Pitchstone in the follow- 

 ing leading divisions : 



1. Simple: a, amorphous, massive ; i, concretionary. 



2. Porphyritic : Pitohstone-Porphyry of mineralogists. 



3. Concretionary spheroidal : Pearlstone of mineralogists. 



4. Amygdaloidal : containing imbedded zeolites, &c. 



The colours are extremely various ; the texture varies from almost 

 glassy to granular, and thus allows of passage into Hornstone. 



PITH is a cellular substance found in the centre of the branches, 

 but not the roots, of Exogenous Plants. [ExoGENS.] 



PITHE'CIA. [SAKIS.] 



PITHE'CUS. [APE; CHIMPANZEE; ORANG-UTAN.] 



PITHYS. [MEHULID2E.] 



PITONNELLUS, De Montfort's name for a genus of Turbinated 

 Testaceous Gastropods, Kotella of authors. [TuRBiMDJE.] 



PITPIT. [DACNIS.] 



PITTA, M. Vieillot's name for a genus of remarkable birds, 

 placed by Mr. Swainson among the M yiottterirue, or Ant-Thrushes. 

 [MERULID.E.] 



Pitta (Vieill., Temm.). M. Lesson remarks that, under the name of 

 Myiothera, Illiger and Cuvier united the Breves of Buffon and the 

 Ant-Thrushes properly so called. These Breves are remarkable, he 

 observes, for the livid colours of their plumage, their long legs, and 

 their very short tail. They are only found, he adds, in the Malaisian 

 Islands, whilst the Ant-Thrushes belong to the New Continent as well 

 as to the Old World. 



Mr. Swainson notices the genus Pitta, as one of remarkable beauty, 

 and observes that they have the gradually-curved bill of the true 

 Thrushes, but much stronger. 



P. gi'jas, Breve Geant, or Giant Pitta. Size equal to that of a mag- 

 pie, but the tail is short and squared, and the wings cover it entirely. 

 A very brilliant azure-blue covers the back, the scapulars, the rump, 

 and tail ; a less vivid tint is spread over the wings, the quills of which 

 are black, covered with azure towards the tips ; summit of the head, 

 nape, and demi-collar of the lower part of the neck black ; feathers 

 of the front and eye-brows ashy-brown ; throat whitish ; an ashy- 

 brown tint is spread over all the lower parts ; the feet are very long 

 and of a horny-ash colour. Total length 9 inches. 



It is found in Sumatra. (Temminck.) 



*- c 



r-^, 



-/1V 



Giant Pitta (Pitta gigas). 



Sub-Genus Chlorisoma. (Sw.) 



C. thalassinum (Kitta thalassina, Piroll Thalassin, Temm.). Greater 

 part of the plumage very brilliant celadon-green ; a velvety black 

 band springs at the angle of the bill, passes backwards so as to include 

 the eye, and surrounds the occiput ; tail deep tarnished green ; wings 

 reddish, but the three or four secondary feathers nearest the body arc 



