PHYSIOLOGICAL 261 



adaptation to mud-sifting; the pelican, with its huge gape, has a 

 small tongue like a toothpick. 



In mammals the tongue has its own muscles, and besides being a 

 taste-organ, it often plays an important part in securing the food. 

 It has been made the subject of an elaborate monograph by the 

 late Dr. Charles Sonntag, anatomist to the Zoological Society of 

 London, The tongue fills the mouth in all mammals except in the 

 duckmole, some rodents, and some of the adult toothed whales, 

 where it lies far back. In ant-eaters it is worm-like and mobile, 

 copiously covered with glutinous secretion, so that it forms a very 

 effective insect-catching instrument. The giraffe has a prehensile 

 tongue, useful in drawing leaves into the mouth, and some bats 

 have a tongue suited for probing into night-blooming flowers in 

 search of insects. Everyone is familiar with the rough papillae on a 

 cat's tongue, which make it feel like sandpaper when puss licks 

 our finger. These strong papillae are characteristic of the feline 

 carnivores, and are usually interpreted as adapted for rasping 

 remnants of flesh from off the bones. But it is very probable that at 

 least part of their significance is in connection with the toilet, for 

 the tongue serves the fur as sponge and brush in one. Another use 

 of the tongue is many mammals is in lapping up water, as we see 

 so well in the dog. Apart from assistance in voice-production and 

 discrimination of food by taste, one of the highest uses of the 

 tongue is in exploring a crevice where something edible may be 

 expected, or in testing the texture and amenities of the food. In 

 some of the half-monkeys, such as Lemur itself, the tongue tests 

 the food very carefully before it is taken into the mouth; and, as 

 Dr. Sonntag wrote: "It must not be forgotten that the human 

 infant gains information of its environment by touching objects with 

 the point of its tongue." 



ANIMAL HYPNOSIS.— One of the oldest of biological tricks was 

 that played by the magicians before Pharaoh when they cast down 

 every man his rod, and the rods became serpents. For, according 

 to the higher criticism, the rods were snakes in a rigid hypnotic 

 state. What Aaron's rod was is another question, for it swallowed 

 all the others. Prof. Verworn tells us in his General Physiology that 

 "by slight pressure in the neck-region it is possible to make a 

 wildly excited, hissing, upstanding hooded cobra suddenly motion- 

 less, so that the dangerous creature can be put into any desired 

 position without fear of its fatal bite". For various reasons we 

 have not tried this particular experiment, but we have verified 

 some others, as with the frog; and the state into which the animal 

 passes is very puzzling. One excitation is antagonised by another, 

 and the creature reacts to the physiological contradiction in terms by 

 becoming stiff and stark. We shall improve on this statement later on. 



