©. A. BARBER. 17 
completely at variance with all that we have seen in the Santalum 
haustorium 
The line of separation appears to be closely connected with 
the gland, and always abuts on the nucleus nearly opposite to 
the middle of the gland, about where the ‘‘cap” reaches its 
lower limit. From the nucleus outwards it passes downwards on 
each side in a well-marked curve, more or less across the lines of 
growth, and terminates either indistinctly in the end of the 
cortical fold or curves round and ends sharply on its inner surface 
(Plate V, figs. 1 and b). 
Obviously some other factor than the more or less meriste- 
matic condition of the tissues enters the case. In fact, the cells 
of the clear region soon Jose their meristematic character and, 
when they reach the clearest stage, are permanent and more or 
less moribund. We may consider the food requirements of the 
developing tissues of the axis. Such would undoubtedly help to 
keep the inner cells of the cortex clear of starch and, with the 
great and sudden development of the gland, these requirements 
are intensified. The upper parts of the nucleus may be presumed 
to be supplied with nutriment by the strands of vessels from the 
mother root. But the needs of this rapidly developing upper 
part and the density of the tissues in this region cuts off, so to 
speak, the lower parts from this source of supplv. The inner 
cells of the cortex are therefore laid under contribution. We 
have seen that at a certain stage the lower part of the gland 
swells enormously and rapidly becomes disorganized with the 
secretion of a mass of glairy substance. It is just at this stage 
that the inner cells of the cortex become cleared of their visible 
contents, and the cells thus cleared are exactly opposite to the 
swelling region of the gland. It appears probable therefore that 
the clearing of the inner cells of the cortex is due to the passage 
of their contents to the developing lower part of the gland. 
And if this be the case, and explains the upward termination 
of the line of separation, it is not impossible that its downward 
continuation may be due to the same cause, less material being 
required as the scene of activity isreceded from. This is not 
