108 VEGETABLE ORGANOGRAPHY. 



class, dispositions really distinct. When the pieces are 

 in two rows, and the outer one is very short com- 

 pared with the inner one, we designate this disposition by 

 the name of Calycular ^Estivation ; but this relates 

 to the proportion, and not to the position of the parts. 



3d. It is possible that there exists in reality an Op- 

 posite ^Estivation, i. e. when each of the pieces of 

 one row arises exactly opposite that of the first row ; but 

 the examples which might be referred to this class are 

 obscure and uncertain ; such would be, for example, the 

 inner petals of Epimedium and Leontice, if we may 

 really consider them as distinct pieces of true petals. 



The cases which I have enumerated seem to me to be 

 the only ones which exist in flowers strictly regular ; but 

 there are cases of slight irregularities, which it is usual 

 to class among aestivations. I ought, perhaps, to have 

 mentioned them in the preceding section, but I hope to 

 do it more clearly in reserving them for this. 



"When the parts of the calyx or corolla are not 

 situated exactly in the same manner with regard to the 

 axis, there is an irregularity, and then one or some of 

 these parts have a tendency to overlap the others during 

 the prefloration ; it is this that a great number of 

 botanists designate collectively by the name of Imbricate 

 ^Estivation, a term which, although become customary, 

 has the inconvenience of being taken here in a very 

 different sense from what is explained above ; and it 

 would be advantageously replaced by that of Irregular 

 ^Estivation, if we wished to have a collective term. 

 It must be remarked, in fact, that this aestivation only 

 exists in irregular flowers, or in those having a tendency 

 to become so ; for it is a deviation from the symmetrical 

 order. We may distinguish several cases sufficiently 

 constant to deserve, perhaps, a special designation. 



Thus, among 5-parted flowers, we often see the pieces 



