NINTH WEEK. 



Three specimens of insects should be determined this week. For 

 directions see under eighth week. 



ELECTIVE WORK. Physiology. 



If this work is elected, the whole of one of the following groups 

 must be done: 



GROUP i. Walking. Needed: (a) For blueprinting: solution of 

 citrate of iron and ammonia, one part to four of water; solution of red 

 prussate of potash, one part to six of water; dish for sensitizing bath, 

 some plain paper not too highly sized. () For tracings: A candle, 

 some small panes of glass; (V) for loading: a little wax or soft paraffin, 

 some shot of rather large size; \d) for experimenting with, a number of 

 insects of the same species and of rather large size. 



TWELFTH WEEK. Sensitize some paper by wetting one side of it 

 with a mixture of equal parts of the above solutions and drying. This 

 should all be done in the dark room. Blacken a sheet of glass by hold- 

 ing it over the burning candle. Lay the blackened glass on the table, 

 and cause an insect to walk over it, and take a blue print copy of the 

 tracing thus obtained. Illustrate by diagramatic sketches the method 

 of walking as made out by a study of the tracings. Fasten a blue print 

 of the tracing into the book. 



THIRTEENTH WEEK. Repeat the above, but with mutilated spec- 

 imens, showing the method of walking with five and four legs instead 

 of the normal number. 



FOURTEENTH WEEK. Melt a little of the wax or paraffin and 

 place a drop on one end or side of the insect experimented with, and 

 imbed in it one or more shot so as to weigh the insect down on that 

 side or end. Obtain tracings as above and compare the results with 

 normal walking. Repeat once or twice with the load at different 

 places. 



FIFTEENTH WEEK. Obtain tracings of the same species on in- 

 clined surfaces and compare with the loaded and with the normal walk- 

 ing. 



SIXTEENTH WEEK. Obtain tracings showing a change in locomo- 

 tion due to a sensation, as a touch or sound, and compare the tracings 

 before and after the change as well as the transition. 



GROUP II. Flight. Needed: A pair of small sharp-pointed 

 scissors, some wax or soft paraffin, some small shot, India ink, a small 

 camel's hair pencil, a vial of chloroform, a number of house flies. 



TWELFTH WEEK. Cut off an equal amount from both wings of a 

 fly, and, allowing it to escape with a normal fly, note the effect of 

 the mutilation. Repeat two or three times, clipping off different relative 

 amounts, but always the same on the two sides. Repeat two or three 

 times, taking parts off from the back edge only. 



THIRTEENTH WEEK. Repeat the above experiments, mutilating 

 only one side, and note results. 



