244 ANIMAL LIFE PAST AND PRESENT. 



whale, of the Arctic Seas, has one enormously, long 

 tusk usually the left one projecting from its head ; 

 while that of the opposite side is quite rudimentary, 

 and remains as a little nodule in the gum, resembling 

 the kernel of a nut in its shell. Among the Hoofed 

 mammals, modern horses usually have but six grinding- 

 teeth in the upper jaw ; but occasionally a small 

 seventh tooth, known as the " wolf-tooth," comes up 

 in front of all the others. This small useless tooth, 

 which falls out at an early period, represents a much 

 larger and useful tooth found in the earlier members 

 of the group to which the horse belongs. Many other 

 mammals possess rudimentary teeth ; thus bears have 

 three little knob-like teeth between the upper tusk 

 and the flesh-tooth, which are of no sort of use, and 

 are soon lost. They correspond, however, to the well- 

 developed anterior cheek-teeth found in the dog and 

 the civet. Many bats, again, show one or more exceed- 

 ingly minute, almost microscopic teeth, wedged in 

 between the larger ones, and clearly pointing to their 

 relationship with other bats in which these small teeth 

 were large and functional. 



Mention must not be omitted of the so-called " vermi- 

 form appendage " of that peculiar little pouch found at 

 the junction of the large and small intestine in the 

 human subject, and known as the ccecum-coli. Not 

 only is this little appendage absolutely useless, but its 

 presence may even be the cause of death, since there 

 is at least one instance known where death has ensued 

 from a cherry-stone having become firmly fixed in it. 



