6 9 
Roots of Cycas Seemanni, A l. Braun . 
in the stem. In all the seedlings investigated the stem 
showed simply a normal ring of collateral bundles without 
any abnormalities of thickening whatever. At the transition 
from root to stem the anomalous zones of the root abut on 
the bundles of the stem, in the way indicated in Fig. 3. 
In conclusion, the general results of the investigation may 
be summed up as follows : — 
1. All the anomalous thickening observed proceeds from 
cells of the many-layered pericambium. 
2. The first anomalous cambium arises in the inner portions 
of this zone. 
3. The second anomalous development starts from the 
extreme outside of the pericambium. 
4. The orientation of the inner anomalous tissues is re- 
versed, the phloem lying towards the centre, the xylem 
towards the periphery of the root. 
5. In the outer anomalous region the orientation is normal. 
That further processes of abnormal development may occur 
in the older root is extremely probable, but this can only be 
determined by the examination of more advanced specimens 
than those at my disposal. 
EXPLANATION OF FIGURES IN PLATE VI. 
Fig. 1. Transverse section of a root of type i, showing a portion of the vascular 
cylinder only. pr. xy. primary xylem plate, pr, ph. compressed remains of primary 
phloem, n. cb . normal cambium, a. cb. x first abnormal cambium, its products 
have reversed orientation, a. cb. 2 second abnormal cambium, z. approximate 
starting points for the development of the first abnormal cambium. The cells 
shaded black contain tannin. ( x about 45.) 
Fig. 2. Portion of a transverse section of a younger root of type 1, showing 
the origin of the second abnormal cambium. The first abnormal cambium has 
already produced numerous permanent elements, e. endodermis. a. cb. 2 second 
abnormal cambium, t. tracheid already derived from it. a. cb. x first abnormal 
cambium. ( x 140.) 
Fig. 3. A. Longitudinal section of the junction between stem and root in type i„ 
B. Transverse section through the root of the same. c. 0. r. common outer ring. 
