VEGETABLE IVORY PALM. 211 
their normal structure: they become 6-rayed, the tubes correspond 
exactly with each other and every one is tipped with a swollen head, 
and more or less filled with the globular substance of which I have 
spoken. Thus we see revealed the whole organization of Vegetable 
Ivory, which is merely a prismenchyme with thickened cells, in which 
the rays of communication are preserved. ‘Fhe closest scrutiny has not 
enabled me to detect in the thick portion of the cells the smallest trace 
of those layers of growth which have been detected by M. Valentin, 
especially in the Hoya carnosa and Oreodoza regia, &c. 
“This substance, which appears continuous, is very analogous to 
that which MM. Schleiden and Theodore Vogel, in their researches 
into the nature of the albumen, have found in the albumen of Phenix 
dactylifera; only that in the latter, there is no starry disposition of the 
tubes, and the hollows of the cells od elongated into two, or, at 
most, into three radii of communication 
M. Morren has well observed at p. 18; ; *livoire qu'on retire de ces 
graines n'est autre chose que l'albumen qui, de laiteux qu'il était 
d'abord, d'albumineux qu'il était ensuite, a fini par acquérir la consist- 
ence du blanc d'amande pour passer enfin à l'état dur, élastique et 
blanc qui l’ a fait comparer à l'ivoire.” 
It isa no less curious fact that this hard eburneous mass again 
reverts to its former soft state in the process of germination. This we 
have frequently had the opportunity of witnessing; our seeds were 
mostly sown in pots, one in each pot, and buried two inches or more 
under the earth. The first symptom of vitality is apparent by the 
protrusion of a strong stout fibre, which quickly takes a downward 
direction, and elongating some inches, produces from the opposite 
extremity a new plant, which soon developes itself in the air, while 
from its base the true roots descend (as shown in our figure, Tab. VIT. 
g. Gradually the seed so recently buried, emerges to the sur- 
face, there lying on the earth; or more frequently, it is forced out 
of the pot, hanging over the edge and suspended by the strong fibre 
before alluded to, which thus forms a medium of communication by its 
vessels between the seed and the very base of the young plants (the 
collum) or point of junction of the root and stem. If at this time the 
seed be broken, the inside will be found to have become a soft substance, 
half pulp and half milk, which feeds the young plant, till it is old enough 
to derive its nutriment wholly from the soil, viz., when the plant is a 
2x2 
