OF INFLORESCENCE. 45 



each flower, or the bracteolcs ; and what, among other 

 circumstances, tends to prove the analogy of these organs 

 is, that these scales are always situated on the outer 

 side of each flower, which corresponds to the lower one 

 of racemes, and consequently their position is the same 

 as that of the bracteoles. When the gradations of form 

 from the leaflets of the involucrum to the scales of the 

 receptacles are carefully followed, no one can doubt the 

 identity of these organs. As they are situated between 

 very close flowers, it frequently happens that they are 

 abortive ; or reduced to a perfectly scaly state, and of 

 very small dimensions ; or, lastly, they are united either 

 with each other, or with the flower. When they are 

 united together by their margins, it results that each 

 flower seems as if it were inserted into a little cup ; this 

 is observed very well in Syncarpha : when they sur- 

 round the calyx, and are combined with it, they seem 

 to make part of the flower, as is seen in Scolymus angio- 

 spermus : but when the two phenomena take place at 

 once, the whole head of flowers does not make more 

 than a single body, apparently hollowed out into semini- 

 ferous holes, and its structure can only be unravelled 

 by very delicate analogy ; we see this in Gundelia and 

 Opercularia. 



When the pieces of the involucrum are large and 

 sheathing at the base, the name of Spathe is given to 

 it, and the pieces of which it is composed are improperly 

 called Valves. This organization is only met with in 

 Monocotyledons ; and when it is mentioned in Dicotyle- 

 dons, it is as if one said that an involucrum had the 

 form or appearance of a spathe. In true spathes there 

 are sometimes one, sometimes two valves ; but in the 

 latter case they are never opposite, but alternate ; 

 and the lower one, which is the larger, embraces 

 by its base the upper one. This organization is met 



