A WASP 3 



for the spiracles, the external openings of the tracheal or respira- 

 tory system ; they appear as a straight row of minute dots on 

 each side of the abdomen and the thorax, one dot being on each 

 segment on each side. In dark-colored wasps it may be impos- 

 sible to see them with a hand lens. They are usually distinct in a 

 caterpillar or a grasshopper, or may be seen in the wasp by re- 

 moving a portion of the cuticula from the side of the body and 

 examining the inner surface under the microscope. 



Exercise 1. Draw an outline of the side view of the wasp on a scale of 

 4 or 5, indicating the segmentation and all the parts observed. 

 The three thoracic segments may be difficult to distinguish at first, 

 but if it is kept in mind that each one of them bears a pair of legs, 

 the task will be easy. Number on your drawing the thoracic and 

 abdominal segments, and carefully label all the different parts and 

 organs. 



Exercise 2, Draw an outline of the face on a scale of lo, showing 

 exactly the relative length and the segmentation of the antennae, 

 the position of the compound eyes and ocelli and the upper lip, and 

 label them all. 



Exercise 3, Remove a metathoracic leg and draw an outline of it on a 

 scale of 5. Its different segments, beginning with the proximal one, 

 that is, the one nearest the body, are the following : the coxa, by 

 which the leg articulates with the body ; the trochanter, a very 

 small segment ; the femur, or thigh, a long segment ; the tibia, or 

 shank, also long ; the tarsus, or foot, which is composed of five 

 small segments, the last one of which bears the two claws. Label 

 all of these. 



Exercise 4. Remove a mesothoracic wing, extend it, and draw a 

 picture of it on a scale of 5, indicating its venation. 



