the squid backwards much as a gun kicks against the shoulder. 

 By turning the funnel one way or another the direction of move- 

 ment can be controlled. 



The eyes of the squid are among its most conspicuous and in- 

 teresting features, resembling in a most remarkable way the 

 eyes of vertebrate animals. Close examination, however, dis- 

 closes the fact that these two types of eye, although similar in 

 appearance, are built up in an entirely different manner. Such 

 a superficial resemblance between structures is termed analogy 

 in contrast to the fundamental identity of such structures as 

 the limbs of the bird, bat, porpoise, horse, sloth, and man, which 

 is called homology. 



Unlike Nautilus, the squid has no external shell but under- 

 neath the skin is to be found a stiffening rod having much the 

 form of a quill pen. One may thus draw pictures or write letters 

 with squid "ink" and a squid "pen." Most remarkable of all, 

 this is even possible with the ink and pen of fossil squids which 

 lived millions of years ago. The ink of cephalopods varies 

 somewhat in color, that of the genus Sepia explaining the ori- 

 gin of the water color of that name. The internal shell also 

 varies and in one genus, the so-called cuttlefish, takes the form 

 of a broad and rather thick, spongy structure which is familiar 

 to all of us as the cuttle bone so commonly fed to canaries. 



These are but a few of the natural history features of a single 

 class of the great phylum of the mollusca. Some of the other 

 classes are just as varied in form and habits and a survey of the 

 group as a whole tempts one to feel that it is the most interesting 

 of all the invertebrate series. Other phyla, however, prove just 

 as fascinating when we really make their acquaintance and the 

 one that seems most interesting is usually the one we happen to 

 be studying at the time. 



P. M. Rea. 



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