A sharp spike at the apex represents the embryo leaves ready
to unfold, while the roots spring from the opposite and slightly heavier
end. The weight is so nicely adjusted that the spindle floats
perpendicularly or nearly so, when owning a separate existence from the
parent tree, it drops into the water, and begins its remarkable career.
It has been suggested that the viviparity of the mangrove is a survival
of a very remote period in the development of the earth--that a mangrove
swamp represents an age when the earth was enveloped in clouds and mist;
and that with the gradual decrease in tepid aqueous vapour the
viviparous habit, then almost universal, was lost, except in the case of
this plant. Other plants, however, exhibit the characteristic. Notably
one of the handsomest of the local ferns (ASPLENIUM BULBIFERUM) which,
with motherly solicitude, detains its offspring until they are not only
fully developed but are strong and lusty. As the fronds die they incline
earthwards, each weary with the burden of a new and virile
generation--some of which float down stream to foreign parts, some create
a colony round the parent. This fern demands conditions similar to the
mangrove--water, heat and humidity--and might be quoted in support of
the theory which gives unique interest to a mangrove swamp.
Pages:
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321