330 M. De Caiulolk an Double FlMeri, [May, 



explain the cause of their monstrosities, as well as their origin, 

 their nature, and their limits. 



There are few families of which the flowers are so much dis- 

 posed to become double as the ranunculaceae ; and their struc- 

 ture explains the cause of this disposition. Since the publication 

 of M. Jussieu's memoir upon this family, botanists have generally 

 been agreed that their flowers are composed, 1 . Of a calyx, often 

 coloured like a corolla, and formed of a certain number of seg- 

 ments, which are almost always flat. 2. Within this calyx arc 

 generally found one or more ranges of petals, sometimes flat, 

 sometimes with two lips, which give them the form of a horn. 

 The petals are occasionally wanting ; for in those plants, such 

 as the clematis, thalictrum, and anemone, where the flower has 

 only one integument, it is rather to be considered as a calyx 

 than as a corolla. 3. Within the petals are to be found many 

 rows of stamens. 4. In the centre of the flower are many ova- 

 ries, each furnished with a style, and often defended at their 

 base by a small membranous scale. 



All these parts may concur more or less in the formation of 

 double flowers ; and in order to explain the nature of the process 

 by which this change is effected, we may take the example of 

 the anemones. A single anemone is composed of a calyx, con- 

 sisting of five or six large petaloid segments ; it is without petals, 

 but lias a considerable number of stamens and ovaries. In the 

 double anemone, florists distinguish four kinds of petals ; the 

 first consists of parts of the calyx, which experience little or no 

 change in their form ; the other three kinds are small. accessory 

 petals, which replace the organs of fructification: 1. Those 

 which proceed from the transformation of the pistils ; 2. Those 

 which surround the centre, and are formed by the transformation 

 of the stamens ; and, 3. Those which are placed in the situation 

 of proper petals, between the calyx and the stamens. The same 

 structure may be observed in other double flowers, and we can 

 always determine what is the origin of the new petals. When 

 the calyx is coloured, it generally produces them ; as is the case 

 with the clematis, thalictrum, caltha, &c. ; the pistils are more 

 rarely transformed; and when they are so, it is always the parts 

 susceptible of receiving colour. The pistillary petals are of a 

 greenish hue, and they compose the green eyes, orhearts, which 

 are observed in some double ranunculuses, or anemones. It 

 happens not unfrequently that in double flowers, the pistils 

 remain in their natural state in the middle of the transformed 

 stamens ; in this case the flower is still capable of being 

 tendered fertile by those in its vicinity, and seeds will be formed 

 from which varieties are produced that will be still more double. 

 When the number of surrounding petals is very considerable, 

 the pistils are, as it were, compressed or stifled, and then the 

 centre of the flower is hollow, as is often the case h} the ranuu- 

 culuses. 



