COR 



gtneris-, which ought to be dis- 

 tinguished by a peculiar denomi- 

 nation; and as it is exceedingly 

 rich in tin and copper ores (being 

 the principal seat of the Cornish 

 mines) the name of cornubianite 

 might be adopted. Cornubianite 

 consists of a basis of compact 

 felspar, coloured by a dark mineral 

 resembling mica, with which it is 

 not only intimately combined, but 

 also contains this mineral in distinct 

 granules, or scales, variously dis- 

 posed. This rock always occurs in 

 contact with granite ; by numerous 

 beds and veins of which, it is 

 frequently intersected. Dr. Eoase 

 enumerates six species of cornubi- 

 anite, namely, compact, quartzose, 

 lamellar, striped, micaceous, and 

 schistose. 



COEO'LLA. (Lat.) The corolla con- 

 sists of the delicate petal, or petals, 

 forming, what, in common lan- 

 guage, are termed the blossoms; 

 and in polypetalous flowers, the 

 petals are usually called the leaves 

 of the flower. The corolla consti- 

 tutes the beauty of the flower, and 

 the odour and fragrance of the 

 plant frequently reside therein, as in 

 the rose, jessamine, violet, &c. The 

 corolla has a diversity of forms, as 

 well as of colour, being found of 

 every shade and variety except 

 black. It includes two parts, the 

 petals and the nectary ; the latter 

 is sometimes a part of the former, 

 and sometimes separate from it. 

 The leaves of the corolla are called 

 petals, and these are either distinct, 

 when the corolla is termed poly- 

 petalous, as in the rose, ranunculus, 

 &c. or they are united by their 

 edges, in which case the corolla is 

 said to be monopetalous, as in the 

 honey-suckle, convolvulus, &c. The 

 corolla is either regular or irregular ; 

 when the petals are all alike in 

 size and form, the corolla having a 

 symmetrical appearance, it is called 

 regular ; but when the petals are 



[ 109 ] C K 



unequal, or unlike each other, it is 

 termed irregular, as in the pelargo- 

 nium, violet, &c. A papilionaceous 

 corolla consists of five petals of 

 particular forms, of which the 

 uppermost is turned back, and is 

 called the vexillum or standard; 

 the two next resemble each other, 

 but differ from the first ; they have 

 their faces towards each other; 

 they are called the alaB, or wings : 

 the remaining two, which are 

 placed below the others, also re- 

 semble each other, but differ from 

 the three already mentioned ; they 

 are usually united by their lower 

 edge, and form a figure resembling 

 the keel of a boat, whence they 

 obtain the name of carina, or keel. 

 This corolla is the characteristic of 

 th Ieguminosa3, a very large order 

 of plants, of which the broom, 

 lupin, sweet-pea, vetch, &c. are 

 examples. 



In some plants the corolla has 

 one or more of its petals spurred, 

 as in the violet. 



In the orchidese, the corolla 

 consists of three pieces, one differ- 

 ing very greatly in form and size 

 from the other two ; it is called the 

 lalellum or little lip, and is often 

 spurred. In many species, this 

 resembles an insect. 



The lower part of the single 

 petal of a corolla, by which it is 

 fixed to the receptacle, is named 

 the claw. 



The cruciferous plants have four 

 petals, and these are so arranged as 

 to resemble a cross, from which 

 circumstance they have been named 

 Cruciferas. The stock, radish, 

 cabbage, mustard, &c. are examples. 



The outer part of the heads of 

 many composite flowers is formed 

 of the ligulate corollas of the ex- 

 terior florets, and these are 

 commonly white, blue, or yellow, 

 as in the aster, daisy, &c. ; this 

 part of the head is termed the ray, 

 the central part being called the 



