402 



In the Corymbosae in particular, we have already seen that the two opercula cohere 

 (or adhere, being of different origin.) A number of cases of double opercula have been 

 enumerated ; following are a few additional notes : — 



E. bicolor.— " Outer lid not always independently developed or very fugacious 

 or consolidated with the inner one." (" Eucalyptographia," under E. 

 largiflorens.) 



A', microcorys. — In this species, even when quite young, one can see a second 

 operculum on every bud of an umbel — on the very top of the bud, i.e., pushed 

 on the top by the force of expansion. 



E. rostrata. — ' Did you notice that on the top of the operculum of E. rostrata there 

 is a small membraneous red cap, as it were a second operculum?" (Rev. 

 Father J. W. Dwyer, Temora, N.S.W.) 



E. - fi has a double operculum. 



E. tetraptera. — The pagoda-like (owing to shrivelling) outer operculum will be 

 figured in due course. 



The Hinged Operculum. 



As a general rule, the operculum becomes severed from the calyx-tube at the 

 time of the ripening of the stamens by a " clean ; ' severance. But in some cases there 

 is more or less irregular tear, that is to say, the inner operculum remains attached to 

 a portion of the calyx-tube by means of what may be termed a hinge, the inner thin 

 membraneous operculum (there are usually in species which tear two opercula) 

 becoming thus irregularly severed. Sometimes the severance is so irregular that 

 jagged is a descriptive word. (See E. pyriformis, fig. 3a, Plate 75.) The outer 

 operculum may not form part of this hinge. Shortly after the emergence of the 

 stamens the operculum (or opercula) ceases to grow, while the calyx-tube continues to 

 develop, as will be shown in figures to be produced later. 



L841. Lindley (1841) was apparently the first to notice the laceration of the 

 inner operculum, where it is attached to the calyx-tube, as, in his description of the 

 operculum of E. calophylla, he speaks of it being fixed to the calyx-tube by a hinge. 



" . . . . the cup is obconical, 6 lines long, and as much across the mouth; the lid, however, is 

 only half that diameter, and hangs to the edge of tin- cup on one side, by a narrow neck, so that it cannot 

 fall off; this arises from the cup continuing to enlarge after the separation of the lid " (this work, Part 

 XLIII, p. 73). 



For a figure of the lid (operculum) which has ceased to grow, and which is 

 adherent to the calyx-tube by a sort of hinge, see fig. 3a, Plate 75, and also the 

 description at Part XVII, p. 229. 



