TttB: TBOt^IOAL AGRIOtLTURmT. I.K0V, 1, 1902, 
slgnificftnce of the rings of growth. In the decidnons 
trees which undergo foliar repletion in the middle 
of the drought and rainy seasons the rings of 
growth would probably be more enhanced when 
produced in the midst ot the hot dry season when 
transpiration was at the maximum. 
Allowing that the above results may be logically 
expected, a number of interesting points crop up 
for consideration. 
la the first place we have to realise that perhaps 
a definite histological differentiation can be effected 
in the secondary xylem purely in consequence of 
the excessive transpiration occasioned by a period of 
excessive drought, which may be eccentric or recur 
constantly from year to year. 
In the second place, if the time of foliar repletion 
for any tree coincides with the only hot dry period 
of the year, as it very often does, the excessive 
transpiration which will most probably occur will 
be met by the differentiation of tracheal elements 
of greater width than those produced during the rest 
of the year when transpiration is reduced. The 
reduced transpiration is a consequence of the air 
being cooler and more moist and the leaves 
becoming cuticularised. Hence the enhancement of 
the rings of growth in consequence of the above 
coincidence- 
This has an important bearing on the relative 
significance of the histological diflerentiations 
according to the time when the plants undergo 
foliar depletion and renewal. If, for instance, 
Pterocarpna echinatns, instead of putting out its new 
leaves during the cool damp month of July, it had 
to do this in the middle of the hot dry month 
of March, the ring of growth would probably be 
considerably enhanced. Similary the significance of 
the rings of growth would be reduced if those trees 
which now undergoes foliar repletion iu March were 
to do so in July. Hence we are bound to conclude 
that the significance of the rings of growth 
of trees which put on their new leaf when the air 
at its maximum temperature and dryness is duo 
in part to the increased transpiration then occurring. 
There are other interesting branches of this 
subject such as (a) the relation of leaf to flower 
production, and (i) the order of defoliation to 
direct light when trees are under open or close 
canopy or under partial shade, but as we are here 
confined to the relation of foliar periodicity to 
the xylem differentiation they need not be here 
discussed. 
The most valuable facts will be obtained by 
studying the behaviour of selected tiees from year 
to year and examining the tissues which have been 
produced during the periods of observation. The 
study was commenced while I was engaged as 
Scientific Assistant to the Director, R B. G., Pera- 
den>ya, and I take this opportunity of expressing 
my gratitude t ) the numerous friends who have, and 
are still assisting me iu this work. 

ANNUAL REVIEW OP RUBBER 
MARKET FOR 1901. 
Khamriscii & Go's, (Livekpocl and London) Annual 
Eeview of the KuBiiEii Market i'or 
TUE Year 1901. 
During 1901 the Kubber Market has not been 
characterized by heavy or exceptional fluctuations ; 
it was ;:gainnot a particularly eatisfaotory one for hold- 
ers and importers of the leading grades, and although 
trade remained exceedingly active throu{,'bout the 
year, the values of all grades of Rubber at the close 
are less than a year ago, and Fine Para shows a 
further recession of ;;d. per lb. and other grades iu 
proportion. The bulk of the stocks of Mtdiuma has 
gradually been exhausted, although it must be ad- 
mitted that the prices realised werp exceptionally 
low and showed an enormous loss to the importers 
or holders, and even the more recent importa were 
disposed of at prices which not alone showed no 
profit, but in most instances the prices realised 
show a considerable loss. The imports of important 
Medium grades have fallen off considerably, and as 
the enquiry has increased for same we do not 
anticipate a further appreciable decline in values, 
and one ought certainly to advocate the encourage- 
ment of a substantial- increase in the imports. 
As regards the quality of Para Rubber, consider- 
able grievance was again cause by the want of care 
in the proper selection of these grades, especially 
from the Island districts, and this has led to 
numerous disputes amongst contracting: parties. 
Trade in Great Britain and with leading Continental 
Rubber works was was fairly good and the stocks 
of raw material at the factories are not large, and 
in spite of the fact that deliveries have been ex- 
ceptionally heavy, the reported consumption of Fine 
Para exceeds that of previous years. The American 
market showed the position there not to be so strong 
except for the first few months, but generally speaking 
the Rubber trade has been busy and the only im- 
portant speculative stocks are held by one leading 
American house, whose position at the close of the 
year was considered very precarious visible supply 
now of Para and Peruvian is 4,618 tons against 4,100 
tons last year. This includes Ami rica with a stock 
of 2,005 tons aj;ainst 1,200 tons last year. 
Should the demand for Para Rubber continue good, 
the statistical position at the end of 1901 is certainly 
a very healthy one. The total for the year's crop 
^from July 1st to December 31st) amounts to 13,680 
tons, this means an increase of 2,400 tons, while 
against this the total increase ot the visible supply gives 
us only about 480 tons, thus about 1.920 more tons have 
gone into consumption, this despite the fact that 
it is well known that the " invisible " supply is 
exceptionally small. Although grave financial dif- 
ficulties were experienced by many holders of 
Rubber, the position of the Rubber market is 
fairly sound, and with constantly increasing con- 
sumption, Rubber must be considered very reasonable 
at present quotations. 
Para Kinds. — At the beginning of the year we 
had to record a brisk enquiry for Pira grades, 
and business on a large scale resulted, but, owing 
to continued " bear " operations, prices quickly ex- 
hibited an important recession, and while Hard 
Fine Para was quoted at the beginning of January 
at 33. lOJd., Soft at 3s. 9d., Negroheads, Scrappy at 
2s. 9id., Island at 2s. lid., Cametas at 2s. 4d., 
Peruvian Ball at 2s, 7Jd., and Slab at 2s. 2d., 
prices declined rapidly during the latter portion of 
the first month, and sales for forward delivery at 
a marked decline were done on a large scale, with 
the result that prices for Para grades receded about 
3d, per lb. by the end of the first three months. 
In America Fine Para was then sold as low as 3s. 
6d., Scrapples 2s. 6|d,, Island Is. lid.. Ball 2s 4d., 
and Slab Is. lid. per lb. We then began to re- 
ceive the first advices from Para of probable short 
receipts, and some important bujers partly relying 
upon these reports bought large quantities, thereby 
causing considerable briskness ; this improvement 
was actively maintained for a few weeks, and as 
high as .3s. lOcl. to 3s. lid. was paid for Fine 
during the middle of April. Other sorts were 2d. 
to 3d. per lb. dearc-r. Soon afterwards, however, 
the market agnin showed signs of weakness, the 
demand being somewhat dragging, and in July Hard 
Fine was quoted at 3s. 8d., Soft 3s. 6d., but a 
temporary reaction iu August resulted in quotations 
agairx reaching 3.^. lOd. to 33. 9d. We ha>e then 
had irregular declines of 2d. per lb., and in Novem- 
ber Hard Fine was as low as 3^. 53d , Soft 3s. 3Jd., 
the lowest of the year. Additional table advices 
from Para of probable short receipts during the 
end of the year and the early months of 1902 brouglit 
about some recovery on less pressure to sell, and 
with very large deliveries and moderate receipts we 
