STRUCTURE, ACTION, AND THOUGHT. 



753 



by the aid of an attempt at a skeleton — the so-called cuttlefish 

 bone. But this has no joint in it, and even the octopus does not 

 amount to much. Articulata with their jointed skeletons have 

 reached such a pitch of social organization as to be held up for 

 examples to mankind, and ants and bees are regarded by some as 

 almost the mental equals, if not the superiors, of some of the sav- 

 age tribes of mankind. But the outside skeleton is a sore disad- 

 vantage, for the animal must either remain without growing in 



Fig. 5. — Section of Head of Femur, to show the arrangement of the fibers of bone so as to 

 give strength to it. (From Donald Macalister.) 



size, or else it must be periodically cramped for room, and peri- 

 odically burst its shell, leaving itself naked, weak, and defense- 

 less. The right thing to do is evidently to do like the vertebrata, 

 and have the hard parts inside, and the soft parts outside ; but 

 the relationship of these parts is a sore task upon the student's 

 memory, and to many a one anatomy is a burden too heavy to be 



VOL. XLII. 51 



