226 PROF. F. E. WEISS ON A BISERIATE HALONIAL 
of this species and as I have also observed in the various specimens in the collections of 
the Manchester Museum. 
In some specimens of Lepidophloios fuliginosus in the Cash Collection, though only 
about half the diameter of the specimen now before us, lignified elements are more 
strongly pronounced and show, where they are obliquely cut, sealariform marking. But 
the proportion of such thickened tracheids is very small in comparison with the 
parenchymatous cells of the secondary zone. 
Outside the secondary tissues we come to the phloem region. As in other specimens 
of Lepidophloios fuliginosus, the phloem area is occupied in this specimen by large cells 
or spaces embedded in a small-celied tissue, which is, however, but indifferently 
preserved, so that the individual cells are not always recognizable (Pl. 24. figs. 7 & 12). 
These large round spaces are characteristic of most stems of Lepidophloios, and have 
been described by Bertrand (1891) in LepidopA!oios Harcourtii as phloem elements. 
Seward (1899), however, after very careful examination, has come to the conclusion that 
this tissue is not a true phloem, but a secretory tissue, the large spaces being probably 
formed for the most part “during the life of the plant by the separation and partial 
disorganization of thin-walled cells.” 
I have given my reasons in a previous paper (Weiss, 1901) for dissenting from 
Seward’s views, and for believing that this tissue is true phloem comparable with that 
of existing Lycopodiacee. 
This conclusion is based upon the examination of some very perfectly preserved 
specimens of Lepidophloios from the Cash Collection in the Manchester Museum, in 
which the large sacs or spaces mentioned above are not present and in which the phloem 
shows a distinct resemblance to that of existing Lycopodia. The spaces appearing 
in the phloem of the present specimen and in most other specimens of Lepidophloios 
I consider due to partial disorganization, previous to mineralization it is true, but mot 
during the life of the plant. ‘That this disorganization is not generally apparent in 
other tissues I think must probably be connected with the fact that the ce'l-walls 
of the phloem in Lycopodiacee are often composed of amyloid, a carbohydrate less 
resistant than cellulose, of which the cell-walls of the other tissues are composed. 
In his criticism of my views Seward (1902), while maintaining his interpretation of the 
tissue under question as of a secretory nature, agrees with me “as regards the probable 
phloem-function of this tissue.” As its position and its connection with the leaf-traces 
render this function most probable, I should prefer to retain for it the name of phloem, 
even were it not identical in structure with that of recent Lycopodiales. But even 
n the living representatives of this group we have a very considerable range in the 
structure of the phloem if we include Jsoétes, for which Scott and Hill (1900) have 
definitely established the phloem nature of the secondary tissue of tabular cells. 
The difference between Seward and myself is, I think, largely one of terminology— 
Seward identifying the word phloem with a tissue possessing a definite anatomical 
character, whilst I use the term to describe a tissue having a certain physiological 
function. 
The examination of the phloem in our specimen, where it has undergone some 
