437 
of Bonnet tites gibsonianus , Carr . 
which are observed in the central portion of the spadix ; only 
the transverse sections of the ‘ cords 5 are here usually much 
smaller and fewer and farther removed from one another. 
On the other hand the small transverse sections of the in- 
terstitial organs are much more numerous and are at length 
almost exclusively present towards the outside (see Plate 
XXV, Fig. 2), as I have before endeavoured to show in 
the Palaeophytologie. Their well-preserved, dark-coloured, 
closely appressed epidermal layers contrast strangely with the 
often indistinct yellowish-brown inner tissue, and appear as 
irregular bands traversing the latter. 
Lastly, the outer layer of the peripheral zone cannot be 
resolved into transverse sections of different members, but 
consists of homogeneous dark-brown rather large-celled 
parenchymatous tissue, which surrounds a considerable num- 
ber of cells with strongly-thickened apparently lignified walls, 
and is covered towards the outside with an epidermis, which 
is present over its entire surface, and impinges immediately 
on the surrounding cataphyllary leaves. Not unfrequently 
sharp and tolerably deep indentations penetrate from without 
into this homogeneous external layer ; these indentations 
are covered with the epidermis, and probably answer to the 
cross-sections of a superficial areolation of the entire fructifica- 
tion ; they are particularly well and clearly seen near the 
base of the spadix in Fig. 12 of Plate XXV. Carruthers has 
endeavoured to illustrate the matter by a figure showing the 
details taken from the base of the spadix 1 . 
If we now examine transverse sections of the spadix lower 
than the one just described, we find the structure essentially 
unaltered, except that we get in addition in the centre the 
transverse section of the upper convexity of the 4 cushion * 
surrounded by the constituents of the central portion already 
described. The lower the section, the narrower is the ring 
formed by this part of it, and the inner layer of the peripheral 
zone also gradually diminishes till at last, in the lowermost 
section, the slender compact tissue-mass of the outer layer is 
1 Carruthers, loc. cit., pi. 60, fig. 3 ; also Plate XXV, fig. 8 of this paper. 
