MODIFICATIONS OP THE FLORAL ORGANS. 185 



It would appear from this, that a verticil of stamens has 

 been suppressed, and these stamens belong fro a second verticil 

 and are therefore necessarily opposite the petals. It is true 

 that the abortive stamens have left no traces of their existence 

 within the corolla, but this does not disprove this method of 

 accounting for their absence, because it receives abundant 

 confirmation from what we see in other orders of plants which 

 are equally defective in the stamineal cirde. Thus . in the 

 natural order Priinulaceae, the general disposition of the floral 

 organs is as follows. A monosepalous calyx of five sepals, a 

 monopetalous corolla of five petals, the lobes of which are 

 situate opposite the sinuses of the calycine lobes, and therefore 

 in their normal position ; and a verticil of five stamens which 

 are directly opposite the petals. The law of alternation is 

 'therefore defective in the staminical circle. We account for 

 the phenomena in the same manner as we explain it in Clay- 

 tonia, on the theoretical supposition that the primary alter- 

 nating verticil of stamens is generally suppressed in this family. 

 We examine the other genera of this family for confirmation 

 of our theory, and we find, that although the primary verticil 

 of stamens is suppressed in most of the corollas of the order, 

 yet this very verticil is present in some of them in an inter- 

 mediate stage of development. Thus in Samolus floribundus, 

 for example, there are found in the sinuses of the corolla, in 

 the normal position of the absent verticil, five sterile filaments 

 which are unquestionably these very stamens in a rudimentary 

 condition. When, therefore, we find in the Claytonia and 

 other plants, a verticil of stamens opposite the petals of the 

 corolla, instead of alternating with those petals, we are justified 

 in supposing that the primary alternating verticil has been 

 suppressed, although we may not be able to recognize any 

 traces of its existence in the corolla. 



