304 
PHYSIOLOGY. 
BOOK II. 
seeds buried in the earth, and from other circumstances, that 
the principal conditions are, 1 . uniform temperature ; 2 mo- 
derate dryness ; and 3. exclusion of light. And it will be 
found that the success with which seeds are transported from 
foreign countries in a living state is in proportion to the care 
and skill with which these conditions are preserved. For 
example, seeds brought from India, round the Cape of Good 
Hope, rarely vegetate freely : in this case the double expo- 
sure to the heat of the equator, and the subsequent arrival of 
the seeds in cold latitudes, are probably the causes of their 
death; for seeds brought overland from India, and therefore 
not exposed to such fluctuations of temperature, generally 
succeed. Others, again, which cannot be conveyed with 
certainty if exposed to the air, will travel in safety for 
many months if buried in clay rammed hard in boxes : in 
this manner only can the seeds of the Mango be brought 
alive from the West Indies ; and it was thus the principal part 
of the Araucaria Pines, now in England, were transported 
from Chile. It may therefore be well worth consideration 
whether, by some artificial contrivance, in which these prin- 
ciples shall be kept in view, it may not be possible to reduce 
to something like certainty the preservation of seeds in long 
voyages. Such, for instance, as by surrounding them by 
many layers of non-conducting matter, as case over case of 
wood ; or by ramming every other space in such cases with 
clay in a dry state. These means seem more likely to answer 
their end than the usual modes of putting seeds in bottles, 
packing them in charcoal, or surrounding them by coats of 
wax — all of which, it is well known, are absolutely prejudi- 
cial, instead of beneficial, to the seeds. In illustration of what 
we have recommended, we may add that seeds are well 
known to travel best in their own pods, or pericarps ; may 
we not suppose that their vitality is preserved in such in- 
stances by the non-conducting quality of the air which the 
cavities of the fruit contain ? " 
