44 INTERNAL ANATOMY. 



ground they are left wholly to their own resources for 

 self-protection. The metamorphosis of the locust is 

 direct, and by this we mean that the insect never passes 

 through a quiescent state, but remains active from the 

 time of its birth. Its development is a straightfor- 

 ward growth from the egg to the adult condition, 

 and is readily understood by pupils. In the books 

 the metamorphosis is said to be " incomplete " and 

 is contrasted with the " complete " or, as we prefer 

 to call it, the indirect metamorphosis of the more 

 speciahzed insects. In teaching, it is obviously much 

 less confusing to use the terms " direct " and " indi- 

 rect," unless the teacher begins with the " higher " 

 insects like bees and butterflies and makes the " com- 

 plete " metamorphosis peculiar to these forms his 

 point of departure. In this case he has, it is true, a 

 standard of comparison, though a purely artificial one, 

 which may make the " incomplete " metamorphosis 

 of the more generalized insects intelligible to young 

 minds. 



The idea, however, that one set of metamorphoses 

 can be more " complete " than another when both be- 

 gin with the Q%g and end with the imago, is an aibsurd 

 survival of the old nomenclature, but has held its 

 place tenaciously in spite of changes in methods and 

 opinions. In the study of living forms far more satis- 

 factory results are obtained by following nature's 

 order ; that is, by beginning the study of types with 

 the simple and passing to the complex, and when 

 this is done with insects, the old descriptive terms of 

 " complete " and " incomplete " cannot be retained. 



In general structure, the young or larval locust (Fig. 



