128 PHILOSOPHICAL NOTES ON 



Asa Gray (" Struct. Bot.," p. 66) says :— " The cladophyl of 

 Ruscus reveals its character further by bearing a flower on the 

 middle of its face, in the axil of a scale-leaf, so that this may 

 consist of two internodes ; or else the flower-stalk may belong to 

 an accessory axillary bud, bearing the scale-leaf close to the flower, 

 and be consequently adnate up to this point with the axis of the 

 cladophyl.* In Myrsiphyllum, the cladophyl exactly counterfeits 

 a leaf in form and texture, as well as in function, and it never 

 bears either scale-leaf or blossom (on its face) ; but the flowers are 

 on slender stalks from accessory buds out of the same axil. The 

 true leaves are represented by thin and minute scales, which may 

 escape notice," that is, the leaf proper has atrophied into a tooth 

 or stipel. 



The fact appears that, in Myrsiphyllum^ the scale-leaf, the 

 cladophyl, and the flowers are all branches from some archaic node, 

 which has continued to develoj) more than two branches from one 

 node (the leaf and the bud) as still happens in the lower plants. 



Husctis androgymis has pinnate branches, with alternate 

 lanceolate cladophyls. The cladophyls have a cluster of male 

 flowers on each margin, while Ruscus aculeatus has them on the 

 midrib of the cladophyl. Midrib and margin, as will be seen 

 further on, are, morphologically, one and the same thing. 

 Reference to Gigartina lanceolata, Fig. 16, will show that it 

 is nothing but an expanded midrib. 



From all the foregoing it would appear that the distinction 

 into leaves and cladophyls will not bear scrutiny. 



The grounds upon which the distinction was made appear to 

 be because it became a dogma that each alternate node normally 

 gave off two branches only — the leaf and the axillary bud. 



Whenever a stem became a cladophyl, that is, when it took 

 up the functions of a leaf, the leaf proper naturally dwarfed into 

 a tooth. Structural;botanists then insisted that, because what they 

 called the leaf did not wholly disappear, it was something different 

 from the stem. They might as well insist that because a leaflet 

 dwarfs into a stipel, it is different from the midrib. They 

 brought as evidence of their right conclusion the fact that the 

 cladophyl of the Xylophylla produces flowers between its teeth. 



* By reference to Delesseria, Fig. 12, it Avill be seen that the midrib of a 

 cladophyl is quite equal to giving off leaves, and, therefore, also flowers. 



