Manchester Memoirs, Vol. xlv. (1901), No. T. 9 



dicated before, and as is seen from the preparations in the 

 Binney Collection, described by Seward,^ to a group of 

 cells. Now since these large spaces are very numerous, 

 and since the large subdivided cells are infrequent, it 

 seems to me that both these latter and other groups of 

 cells, probably the star-shaped groups, have become dis- 

 organised to form the large lacunar region. Moreover, 

 as the septa indicate, these groups of more elongated cells 

 would follow each other in vertical series for some distance, 

 and thus afford a tissue well adapted for conducting 

 purposes. These groups of cells were closely set together, 

 as can be seen both in the perfectly preserved specimens 

 under consideration and also from those in which the 

 lacunae take the place of these groups of cells {see Plate 

 III., Fig. 3, in Seward's paper on Lepidophloios). Thus, 

 though we do not get a complete vertical continuity, yet, 

 by lateral passage of adjoining groups of conducting cells, 

 continuous conduction would be possible. It seems to 

 me, therefore, that the tissue occupying the phloem area 

 of Lepidophloios would satisfy all the conditions of a 

 conducting tissue and might be dignified by the name of 

 phloem. It would consist of groups of more elongated 

 cells, arranged for certain distances in vertical series. 

 These groups consisted, as far as we can see from transverse 

 sections, of a larger central and smaller peripheral cells, 

 each group either oval or star-shaped m outline, and would 

 seem by their mode of origin to correspond to the sieve 

 tubes and companion cells of the higher plants. Besides 

 these there were numerous short parenchymatous cells 

 which surrounded the groups of conducting cells (the 

 lacuna in the defective specimens) and these short 

 parenchymatous cells seem to have been more resistant, 



1 Seward, loc. cit. Fig. 5, p. 151- 



