ADAPTATIONS 



413 



spiders spin a web which entangles small insects which come 



in contact with it. Many other animals set traps. Some 



aquatic insect larvae construct a 



trap like a fish net and these open 



up stream, so that the current may 



sweep small edible objects into 



them. The angler fish lies on the 



bottom, of ten very much concealed. 



His most capacious mouth opens 



upward and above it hangs an 



attractive-looking bait, which is 



phosphorescent in some cases. 



When the prey approaches near 



enough the great mouth opens 



suddenly and the rush of water 



into it carries the prey along. An 



African snake (Dasy-peltis) feeds 



largely on eggs,which are swallowed 



whole. Some of the vertebrae have 



pointed processes which project 



into the oesophagus. The shells of 



the eggs are broken against these 



points and the empty shell is then 



disgorged. 



845. Pollination. Some of the 

 adaptations of plants, with regard 

 to pollination, have been noted 

 elsewhere, but there are many 

 special cases which are very re- 

 markable. We can only note 

 briefly a few of them. 



846. The papilionaceous bios- which the f 00 d is strained out of 

 som of most members of the the water - 



pea family is familiar to everyone. This flower in its prime 



FIG. 250. Part of one of the 

 horny baleen plates (" whalebone ") 

 which hang from the upper jaw of 

 the baleen whale. One edge of the 

 plate is split up into a fringe of 

 hairs which form the filter through 



