55 



these vessels, with a common condensed integument or 

 * bark/ constitutes the branches and trunk of the com- 

 pound whole, which is called 'Tree/ A generation of 

 leaves, the breathing parts of the individual phytons, pe- 

 rishes each year ; but not before each individual has made 

 preparation for its successor by developing a bud at the 

 axil of the leaf, which remains when the leaf falls, and sup- 

 plies its place in the following year. Here the individuals 

 are successively propagated by gemmation, as in the Hydra 

 and Tubularia indivisa, but continue associated together 

 like the compound polypes. In order to effect a multipli- 

 cation of plants at a distance from the parent, the common 

 respiratory and gemmiparous form must be developed into 

 a higher condition of individual plant. This begins by the 

 suppression of the bud at the axil, and by the consequent 

 concentration of the formative force in the act of metamor- 

 phosis and individual development. The ( whorl/ or group 

 of such leaves in verticillate arrangement, constitutes what 

 is termed the f calyx': the calyx, then, consists of a group of 

 metamorphosed and often more or less connate or confluent 

 individuals, usually deprived of the power of gemmation : 

 but their tendency to resume the more typical form of the 

 individual the leaf must be familiar to all who have 

 looked at this part in the proliferous roses. The cowslip 

 shows the small amount of change which converts a leaf 

 into a sepal. 



The corolla consists of a whorl of more modified e leaves/ 

 called petals ; and incloses a third e whorl ' of still more 

 metamorphosed forms of the archetypal plant, called sta- 

 mens : in these we see that development has advanced to 

 the establishment of the true male individual, which, like 

 the male in the Lernaea according to Nordmann, the male 

 of the Argonaut according to Kolliker, and the male of the 

 Rotifer according to Brightwell* and Dairy mple, is re- 

 stricted almost to the function of elaborating the fertilizing 

 * ' Fauna Infusoria of Norfolk/ pi. 1. p. 2. 



