A CENTIPED. 63 



Ahead of these come the first maxillae, less conspicuous on 

 account of the absence of a projecting palp. Between the first 

 maxillae and the labrum are the real jaws or mandibles, 

 h) Note the slit-like openings in the soft integument of the sides of the 

 body just above some of the legs. These are the spiracles 

 opening into the tracheal respiratory system. On which segments 

 do they occur ? 



Exercise 2. Draw a ventral mew of the head on a scale of six, showing 

 the mouth parts in position. 



Exercise 3. Remove the poison jaws and the mouth parts carefully and 

 draw them separately on an enlarged scale. 



The internal anatomy of the Centiped will not be considered here 

 as it is similar to that of the grasshopper, which can be more con- 

 veniently dissected. On the whole, however, the internal organs are 

 less complex than the corresponding organs of an insect. This we 

 would expect of an animal which showed less external specialization 

 than an insect. 



