SIXTEENTH WEEK. 



The work of this week is elective. For directions see under 

 twelfth week. 



ELECTIVE WORK. Morphology (con.) 



GROUP IV. The cranium of the wasp. Needed: A small beaker. 

 A wash bottle. A pair of small sharp-pointed scissors or sharp-pointed 

 knife. A number of wasps. 



TWELFTH WEEK. Put about a dozen heads to soak in the beaker, 

 and let them macerate for two weeks. Take other specimens and care- 

 fully study the external structure, drawing from above and from before, 

 paying particular attention to traces of nearly obliterated sutures. 



THIRTEENTH WEEK. Draw and study the head very carefully 

 from the side and from behind. 



FOURTEENTH WEEK. Take the material that has been soaking, 

 and with the wash bottle clean out the inside. Remove carefully the 

 mouth parts and antennae. Put the specimens all to soak again, taking 

 them out only as needed. Take a specimen, and from the neck open- 

 ing cut through the head below the eyes and antennae. Dry and study 

 the internal configuration of the crown, comparing it with the outside. 

 Study several specimens. 



FIFTEENTH WEEK. Cut up the side of the head from the mouth 

 opening through the eyes, and study carefully the internal configura- 

 tion of the face. 



SIXTEENTH WEEK. Cut in the median line through the neck 

 and mouth openings and study the side of the head. 



GROUP V. Development of the honeybee. Needed: Two dozen 

 three-dram vials. Two watch glasses. Two large cover glasses. A 

 comb of brood in all stages. 



TWELFTH WEEK. Examine carefully the heads and determine 

 by their size the number of stages represented. Take a number of 

 each, including the eggs and full-grown bees, and place each stage by 

 itself in vials of 50 % alcohol, and after two hours change to strong alco- 

 hol. Fix another set by first treating in hot water, as directed under 

 the second group, and puncturing in several places before putting into 

 alcohol. 



THIRTEENTH WEEK. Study the three youngest stages of both 

 sets, studying them in alcohol in the watch glasses. Be careful that 

 the upper side of the cover glass remains dry. Describe the stages 

 and the changes undergone. 



FOURTEENTH WEEK. Study the remaining stages to where the 

 wing cases appear. 



FIFTEENTH WEEK. Study the stages bearing wing cases. 



SIXTEENTH WEEK. Study the change to the adult condition. 



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