209 
Anatomy of the Opki'oglossaceae . /. 
him to show the presence of tracheides 
mixed with the pith-cells. 1 It need only 
be added regarding this feature that 
tracheides occurred in the middle of the 
pith of the adult region of this plant 
close to the apex. Their position and 
that of the tracheides figured by Bower 
are indicated in the reconstruction. This 
plant is of interest as showing a direct 
and gradual transition to the adult type 
of stele without the intervention of any 
marked intermediate region. The leaf- 
gaps are all short, and below the adult 
region they are at once closed by endo- 
dermis. There is nothing in the struc- 
ture of the plant or in the endodermal 
relations to suggest that its pith is in 
any way due to intrusion of cortex, 
while the position of the tracheides in 
the pith seems direct evidence against 
this. 
Plant B, the stele of which is re- 
constructed in Text-fig. 4, shows a di- 
rect and even more rapid transition to 
the adult type of stelar construction ; in 
it also there is no internal endodermis 
and nothing suggestive of cortical in- 
trusion throughout the whole plant. 
The slender solid strand of xylem at 
the base of the plant increases in dia- 
meter on passing upwards ; scattered 
parenchyma cells appear in it and then 
a definite pith is established. Four roots 
are attached close together in the region 
below the first leaf-gap. The small leaf- 
trace in relation to this dies out in the 
cortex, and the leaf-gap closes at once ; 
unfortunately the endodermal markings 
were not very clear, but the relations 
appeared to be similar to those at the 
lower leaf-gaps of the preceding plant. 
On the closure of the leaf-gap a root- 
T ext- fig. 4. Reconstruction of the stele 
of plant B. Description in text. 
1 Bower, loc. cit., PI. XLV, Fig. 10. 
