524 Brebner. — On the Anatomy of 
successfully carried out, is that the endodermis shows up 
well, being distinctly stained red, thus contrasting with the 
dark purplish-blue of the cellulose-walls of the ground- 
tissue and phloem. In cases where sieve-tubes were required 
to be distinguished, dilute glycerine (50-70 per cent, glyc.) 
and safranine, or glycerine jelly and safranine were used. 
Beginning at the base of a very young seedling, or older one 
if the base is not decayed, the vascular axis of the stem is found 
to consist of a haplostele 1 . The mode of transition from the 
diarch actinostele of the root to the haplostele of the stem 
was described in a paper on the prothallus and embryo of 
Danaea simplicifolia , Rudge 2 , and agrees in every essential 
respect with the state of matters found by Farmer and Hill 
in Angiopteris. With regard to the first and earlier roots of 
Dajiaea , the protoxylem not infrequently abuts directly on 
the endodermis, or is separated from it by one pericyclic cell 
either at one or both ends of the diarch xylem-plate, but 
in this it does not show any essential difference from many 
other roots. The following quotation from Farmer and Hill’s 
paper 3 might have been written for Danaea simplicifolia : — 
‘ The diarch xylem-plate of the root loses its definite outline 
owing to a considerable increase in the number of its tracheids 
that appear at the sides of the plate, which causes the wood 
to be roughly circular in transverse section ; at the same time 
the protoxylem loses its individuality and the diarch character 
becomes entirely lost. The phloem also extends over the 
periphery of the wood.’ In Danaea , as in all the Marattiaceae, 
the sieve-tubes are distinguished by their relatively thick and 
glistening walls, and by the proteid-granules applied to their 
pitted areas. The sieve-tubes, however, often do not show 
up well in Canada balsam preparations, although the phloem 
as a whole is nearly always readily distinguishable. In 
seedlings they are very small, compared to the size they 
attain in the older plants, but are of the usual Marattiaceous 
type. In Danaea seedlings, unlike Angiopteris^ the pericycle 4 
1 See definition in Introduction. 2 Loc. cit. 
3 Loc. cit., p. 384. 4 Cf. Farmer and Hill, loc. cit., p. 385. 
