489 



Hooker, 1844. In the original description of E. maculata, Hooker observes : — 



" The lid or operculum is double; the inner one is membraneous; the inner one has justly been 

 considered by Mr. Brown as the corolla, and it here forms an exactly hemispherical glossy membranaceous 

 cup, which often continues to adhere after the outer one has fallen away." (See Part XLIII, 84.) 



(1) The ordinary single operculum, probably corolline. Bentham, 1866, says — 



''• . . . the orifice (of the calyx- tube) closed by a hemispherical conical or elongated operculum 

 covering the stamens in the bud and falling off entire when the stamens expand, this operculum usually 

 simple (formed of the concrete petals ?), thin or more frequently thick, fleshy or woody, the veins 

 longitudinal, numerous and parallel or rarely anastomosing, the separation from the calyx-tube 

 usually but not always marked in the bud by a distinct line . . . ." (B. El. iii, 185) " .... 

 the operculum described is always the single one, probably representing the petals, as it appears when 

 ready to fall off for the expansion of the stamens." (p. 187.) 



(2) The two thin opercula, the outer calycine, and the inner corolline. 



" . . . . there is also frequently in the very young bud a very thin membraneous external 

 operculum more continuous with the calyx-tube and very rarely this external one persists nearly as long 

 as the internal one and is as thick or nearly so." (B. Fl. iii, 185.) 



" The outer one, of whose nature there is still much doubt, exists probably in nearly all species at an 

 early stage (my italics), but it is usually thin and falls off too soon to be worth mentioning in descriptions. 

 Where, as in E. platyphylla, it persists rather longer, it appears to do so in a very variable degree in the 

 same species. It is only, as far as hitherto observed, in E. variegata and E. eximia that it is more constantly 

 persistent till nearly the time of expansion of the flower, and equals or exceeds in thickness and consistency 

 the inner one." (p. 187.) 



(3) E. maculata. 



" Operculum .... the outer one much thicker and more persistent than in most species, 

 where it lias been observed, and usually umbonate or shortly acuminate, the inner one (corresponding to 

 the single one of most species) thin, obtuse, smooth and shining." Bentham (B. Fl. iii, 258) unde r 

 E. maculata. (See also fig. 4a, Plate 178.) 



(4) E. eximia. 



" Operculum broadly conical or shortly acuminate, always much shorter than the calyx-tube, and. 

 double, as in E. maculata, but the inner one not readily separable in the dried specimens till the flower is. 

 ready to open." (B. Fl. iii, 258, under E. eximia.) 



(5) E. Behriana. 



" Operculum short .... the outer membraneous one often still persistent in the advanced 

 bud. (B. Fl. iii, 214.) 



Mueller, 1879-1884, speaking of the genus says (Introduction to " Bucalyptographia," 1) 

 "Petals none, unless represented in some few species by an inner separate or separable opercular 

 membrane." 



(2) lid (operculum) not rarely provided with a minute early dropping accessory 



outer layer." (ib.) 



(3) " Lid thin, imperfectly double almost hemispherical .... inner lid tender mem- 

 braneous." (E. eximia in " Eucalyptographia.") [Italics as in original.] 



Further, Mueller says " The lid of E. eximia affords excellent material for tracing the metamor- 

 phosis of a calyx into a corolla, and gives in this genus additional evidence for estimating the nature of 

 the opercular organ ; it shows that the ordinary lid of Eucalyptus flowers must be regarded as calycine, 

 though it may consist of two layers, the outer of which, when it occurs, being sometimes fugacious and 

 occasionally minute. The homogeny of the opercular with the tubular portion of the calyx is clearly 

 evidenced by the species of Eucalypts pertaining to the series of E. corymbosa, as pointed out previously 



