130 PBINCIPLES OF fLANT-TEKATOLOGY. 



those further to the inside which are formed from the 

 stamens; they are also approximately of the same size, 

 and are in the same spiral series. These facts being so, 

 is it likely that these two or three outer sepals have 

 had a different origin from the innermost ones ? 



In Salix the perianth (calyx) is in the form of mere 

 glands ; Celakovsky saw these in " a quite leafy" con- 

 dition ; Hegelmaier observed them united to form a 

 kind of lobed ring. 



Bracteody. — The tendency in both floral a.nd vege- 

 tative shoots is to form new organs from above down- 

 wards ; it is rarer for foliage-leaves or bracts to be 

 carried upwards by suppression of internodes or other- 

 wise. Hence the bracts of Anemone and the tulip are 

 here regarded as having been derived from the calyx. 

 In the tulip we constantly see a sepal displaced down- 

 wards (by development of an internode) and becoming 

 foliaceous, while its place is taken by a petal, whose 

 place in turn is filled up from the androecium ; this 

 process involves an vipset of the cyclic arrangement 

 and consequent twisting of the peduncle. In support 

 of this view it may be mentioned that in a plant of 

 Anemone coronaria var. chrysantliemiflora which was 

 observed in Kew Gardens there was an extra whorl of 

 three foliaceous bracts immediately above the normal 

 one ; in other flowers the foliaceous bracts of the 

 extra whorl are represented by petaloid leaves ; or 

 these leaves may form part of a third whorl slightly 

 higher up still. Now, it is clear, or at least, very 

 highly probable, that these extra whorls of bracts 

 have been derived directly from the calyx, within 

 which is a well-nigh inexhaustible supply of stamens ; 

 while it is very difficult to imagine how this entire 

 involucral system could have been projected upwards 

 from that of the foliage-leaves, the number of which 

 is extremely limited. If this is the case, then we must 

 regard the normal trifoliate involucre as having also a 

 floral origin, and not regard the calyx as having been 

 derived from the involucre. 



