Fortunate Islands 
have been most carefully studied, and indeed their story 
is a romance in itself. 
There are from 80 to 120 of these navigators 
belonging to the most various orders, but all are well 
able to take a long sea voyage. 
Their seeds or fruits are able to float for a very long 
time without being in any way injured. Czsalpinia, 
for instance, has been allowed to float for two and a 
half years in salt-water, and many others have survived 
for a year and have germinated successfully afterwards. 
Czesalpinia bonducella has been carried from across 
the Atlantic to the Orkneys, Ireland, Hebrides, and 
Scandinavia, and also to St. Helena. Robert Brown 
succeeded in growing a plant from one of these Ameri- 
can-Irish seeds. 
Perhaps another of them (Entada scandens) is an even 
more efficient navigator, for it has been found in the 
Azores and in Nova Zembla, as well as in all the places 
just mentioned. Seeds from the Azores germinated 
at Kew.5 
These two are Leguminosz and are able to float in 
consequence of their hard, woody, and hollow pod, which 
is in fact very like two shallow wide punts joined together 
along their sides and enclosing the seed in an air-tight 
compartment. 
Most of the navigators have porous or buoyant tissue 
somewhere in the fruit or seed due to air cavities or 
hollows. 
Now waterside plants and especially submerged 
plants are always remarkable for the number of air 
channels or intercellular spaces. Such cavities are 
almost always to be found in water plants, and are due 
to the special necessity of preserving oxygen when sub- 
merged or growing in mud. So these navigator plants 
again show a strange example of fitting reaction. This 
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