112 



THE INFLORESCENCE. 



The Corolla. The arrangement of tho various parts of the plant upon the stem ia 

 agreeable to a definite course in obedience to a known law, as already intimated, 

 commencing with that of leaves and ending with the ovary. It has also been stated 

 that each foliaceous organ is normally formed separately and not in pairs, or in greater 

 numbers, and as the parts are not produced on the same plane or in right lines, but at 

 different heights and in a spiral manner, each one appears to be alternate to the other. 

 "When the parts are widely separated this is readily apparent, but when they are brought 

 close together, the observer is disposed to doubt the fact. Yet in such instances they 

 are never so closely arranged that they occupy, or appear to occupy, the same spot, but 

 are placed more or less side by side, and by multiplication ultimately encircle the stem, 

 and are said to be in whorls. Such whorls of leaves oftentimes seem to be on 

 the same horizontal plane ; but if such be really the case, it is an exception to the 

 established rule. Thus it will be evident that the whorls of leaves taken collectively, 

 cannot be on the same plane, but must be relatively above and below it ; and also that 

 each member of the whorl will be alternate with a corresponding member of the whorl 

 above and below it. Such is the rule, liable to many exceptions ; and when, as excep- 

 tional cases, leaves are found opposite or in whorls and not alternate, it is assumed 



that an intermediate leaf, or set of leaves, has 

 been suppressed, or that the opposite or 

 whorled leaves have each really split into 

 two, and thus doubled the original number. 

 This is a difficult subject for investigation, 

 but it is highly probable that the former 

 theory is correct. From this statement the 

 reader will infer, that if the development of 

 the tree begins with the formation of leaves, 

 and ends with the production of fruit, the 



leaves and * P 8 * 8 between them and * 



flower, showing that the members of each fruit must be situated below the fruit. Thus 

 whorl are alternate with those of inner and -i v_ a _f a nvA rJa,,^ a ^ n ^^ f>iP lan-o-pa tTio 

 outer whorls, a represents the whorl of the tne bracts aie P laced above the leaves, tne 

 calyx, 6 the whorl of the corolla, c the whorl calyx above the bracts, the corolla above 

 pLr r ov a f ry he8tamenS ' "^ * ** "^ the calyx, the stamens above the corolla ; and 



finally, we arrive at the pistil or centre organ 



of the whorle. The relatively external and alternate position of the various parts of 

 the flower are well exhibited in the outline sketches in Fig. 206. 



A knowledge of this fact is a fundamental one in botany, and enables us, at this 

 point of our subject, to include all the parts within the term corolla which lie between 

 the stamen internally and calyx externally (Fig 203.) ; and, moreover, whenever the 

 calyx and corolla are not very distinct from each other, the inner whorls of leaves are 

 thus appropriated to the corolla. 



The corolla, then, is distinguished from the calyx by its normally superior and 

 alternate position ; but it has a further characteristic in being unusually gaily coloured. 

 It is that part to which the term flower is commonly restricted in ordinary 

 language, and is longer and larger than any other part. It is almost invariably 

 caducous, and falls very soon after the impregnation of the inclosed organs When it , 

 consists of one piece, it is termed mono-petalous ; and when divided into several pieces, 

 its divisions are known as petals ; and the corolla is tri-petalous or poly-pet zlous, accord- 

 Ing to the number of its petals. The number of petals is very variable ; and whilst it 



