44 NATURAL SCIENCE. yan, 
swarms of bees. By far the greater number of insects are nocturnal 
in their habits, and, as might be expected, white flowers are very 
plentiful. This makes observation so very difficult, as few of the 
insects can be seen at work. Now and again, however, a belated 
moth may be seen taking a last sip in the early morning, but such 
Cases are rare. 
After the contrivances for fertilisation, those by which fruits are 
protected and disseminated are most interesting. Nearly all those of 
our tables have thick skins, often charged with acrid secretions. 
These have acted so well that fruit-eating flies and wasps are almost 
wanting in Guiana. Birds, however, peel some of them, while bats 
succeed in utilising all except perhaps those of the orange family. 
In the forest the variety of pods, capsules, berries, and other seed- 
vessels is almost overwhelming. Perhaps the most useful develop- 
ments which are common to almost all are those by means of which 
they float and are carried long distances by water. This object is gene- 
rally attained by means of spongy pericarps, but many other devices 
are common, all helping to spread the seeds over very wide areas. 
In the Lecythidez we have apparently protective contrivances against 
monkeys. The Brazil nut (Bertholettia) has a hard, woody capsule 
without an opening, which falls to the ground entire. In the genus 
Lecythis there is a cover which falls off when the nuts are ripe, and 
allows them to scatter in every direction. It is probable that 
monkeys try to get at these, and by loosening the covers let them fall 
out without being able to secure more than one or two. The 
cannon-ball tree (Couwvoupita) has a softer covering, but this smells so 
very disagreeably that neither monkeys nor rodents will touch it. 
Other natural orders repel animals in different ways. The short 
brittle hairs on the cowhage (Mucuna) pods would undoubtedly prove 
more than distasteful to bird or beast, as would also the prickles on 
the. seed-vessel of the Allamanda. Sometimes the seed itself is 
protected, while the covering or pulp surrounding it is obviously 
intended to attract. In such cases birds assist the tree by scattering 
its seeds, and are therefore invited. In the bignonias, so 
common along the banks of the rivers, the seed has a delicate 
membranous expansion, on which it floats in the air like a butterfly. 
Other climbers have feathery appendages, while the stately Tviplavis 
lets its seeds sail down like shuttlecocks. 
Fibrous coverings to the stems are common among the tropical 
weeds. Exposed as these are to vicissitudes unknown in the forest, 
they have developed contrivances distinct from those of the trees. 
The most common mode of overcoming the difficulty of a dry season 
when the roadsides can no longer supply sufficient moisture is the 
faculty of ripening seeds before this takes place. In the forest, 
every plant is a perennial, but annuals are common on the dry 
savannahs, as well as on waste land in the townsand‘villages. Many 
weeds are not only repellent to man, but even to domestic animals 
