A480 CALYX-TUBE. 
Calyx-tube—In descriptive botany it is the common 
practice to speak of a calyx-tube, by which is meant a 
tubular or sheathing portion at the base of the flower, 
below the sepals or calyx-lobes, and distinct or imsepa- 
rable from the ovary. The question morphology has 
to solve is whether this tubular structure is to be con- 
sidered as a portion of the axis, or whether it 1s to be 
regarded as composed of the confluent bases of the 
sepals. 
Mr. Bentham, who has recently reviewed the evidence 
as to the nature of the calyx-tube in his paper on 
Myrtacee,' still holds to the notion that the ‘‘ calyx- 
tube” or “hypanthium” is formed from the concretion 
of the basal portions of the sepals. He founds his con- 
clusions upon such facts as the following: the circum- 
stance that the point of origin of the leaf is not always 
the same as the point of disarticulation or separation 
from the axis, inasmuch as the basal portion of the 
leaf is often adherent to the stem for some distance, 
though still recognisable as foliar not axial in its nature. 
In the same manner, the corolla and andrcecium may 
be concrete at the base, so that the stamens are for 
convenience’ sake described as inserted into the tube of 
the corolla, though it is generally admitted that both 
stamens and petals are really hypogynous, and it is 
not usual to consider the corolla-tube up to the diver- 
gence of the stamens as part of the receptacle. <A 
similar remark applies to the carpels and _pla- 
centas. Mr. Bentham further considers that the 
gradual disconnection of the various whorls, that may 
be traced in many plants, is a further proof of concre- 
tion, rather than of expansion of the axis, but this 
argument may fairly be met by the consideration that 
the several whorls emerge at different heights.” 
Organs originally free and distinct become ultimately 
combined at the base by the gradual protrusion from 
1 « Journ. Linn. Soc.,’ vol. x, p. 103 ef seq. 
2 See also the receptacular tube (ovary ?) of Baeckea bearing stamens, 
see p. 183. It would be natural to see stamens springing from the recep- 
tacle but not from the ovary. 
