Anatomy of Teratological Seedlings . IV. 477 
midrib occurs, leading to the formation of a pseudo-concentric bundle. The 
other also becomes pseudo-concentric. A minor concentration also takes 
place on one of the laterals (Fig. 78, b), so that three mesarch bundles pass 
into the apex of the hypocotyl. Each of these is for a time completely in- 
vested by phloem, but as the bundles move towards the axis of the seedling 
the phloems open on the inner side and their free margins unite so that 
a common ring surrounding the whole of the xylem is formed. The con- 
tinuity of this ring is permanently broken opposite the now exarch proto- 
xylems and also locally throughout, but otherwise there is no further change 
until the formation of the solid xylem core, which heralds the formation of 
Figs. 75-80. A goblet-shaped amphisyncotyl, showing an abnormal type of transition. 
the lateral roots, is well forward. At this stage a new protoxylem pole arises 
between the strand continuous with the permanent lateral and one of the 
midrib strands. This pole gives rise to a lateral root, as does one of the mid- 
ribs (Fig. 80), and the third lateral root of the series appears to be derived 
from the lateral and the second midrib jointly, a most unusual state of 
affairs. The tap-root is tetrarch, the four poles represented in the base of 
the hypocotyl persisting unchanged. 
‘ Seedling F ’ (Figs. 13 a, 13 b, 13 c ) is also goblet shaped, and sections 
reveal the fact that it possesses three fused cotyledons, that is to say, it is an 
amphitrisyncotyl. A trisyncotylous seedling of Centranthus ruber has been 
described by Miss Bexon ( 1 ), and a somewhat similar seedling of Acer 
pseudoplatanus has been collected by one of us, but neither of these exhibits 
