15 
Sections were made through all parts of the pineapple plant from the 
base of the stem to the crown with the result that the distribution of 
starch is found to be strictly in harmony with the chemical findings 
of the ripening of the fruit. In the dead and partially decomposed 
basal end of the stem there is relatively little starch, and that which 
is present is for the most part removed some distance from the fibre- 
vascular tissue. The parenchyma cells in the stem, with the except ion 
of the dead base, are completely filled with starch ; in fact, these trunks 
apparently contain as high a percentage of starch as potatoes or other 
plant structures used in the commercial manufacture of starch. The 
station has planned some experiments to show whether old pineapple 
stumps which have heretofore been thrown away may be used com- 
mercially for obtaining starch. The storage of starch continue- 
upward to the attachment of the uppermost regular leaves, where it 
suddenly ceases. As sections are made in the fruit stem above this 
point, it is found that starch is almost entirely absent up to the point 
where the small bracts are attached to the base of the fruit. Here, 
especially in normal plants, the accumulation of starch is quite con- 
spicuous. 
In the very young fruit at flowering time small granules of starch 
may be found at the base of the bra-cts under each eye and occasionally 
throughout the substance of the fruit. At the base of the crown 
leaves there is a considerable accumulation of starch and a few gran- 
ules are found in the core. The crown in young fruits contains a 
large quantity of starch. 
It is a peculiar fact that old stumps connected only by means of 
a dead stem with ratoon stems contain fully as much starch as the 
latter. The old stumps are known to be capable of producing pine- 
apple plants and have been especially recommended for highly man- 
ganiferous soils. It is likely that in such cases the plants are able 
to develop from the large supply of starch found in the stems. 
Starch is quite abundant throughout the length of all normal leaves. 
When the fruit is about half grown it contains only an occasional 
starch grain here and there just underneath the green epidermis. 
In ripe fruit it is almost impossible to find even a trace of starch 
in any part of the fruit. It is evident from this distribution of 
starch that the source of material to be modified by hydrolysis into 
sugar is almost exclusively outside of the fruit. The few granules 
of starch found under the green epidermis of unripe fruit and the 
small quantity of starch in the crown are insufficient to make any 
practical addition to the sugar content of pineapples which are 
allowed to ripen after removal from the plant-. 
In this connection it is interesting to note the fad that some pine- 
apple grower- consider the crown as a parasite of the fruit or as 
[Bull. 28] 
