ARTHROPODA 271 



Appendages. — Antennae, oral, thoracic, abdominal. Number and general 

 character of each. Where and how are the egg-cases attached? 



Sense Organs. 



Eye-spot (appearing as one, from which the name Cyclops). 

 Do you find any organs which suggest a tactile function? 



Report on all available points of physiology: as food habits; methods of locomo- 

 tion; reaction to light and other stimuli. 



308. Comparisons. — Collect all the minute fresh-water Crustacea possible and 

 compare them with Cyclops. Learn to identify them by their manner of moving 

 in the vessels of water. Daphnia is especially favorable for microscopic study on 

 account of its semi-transparency. 



309. Spider (any common species large enough for study). 

 General Form. — Study the relations of head, thorax, and 



abdomen. Are there any antennae ? Oral appendages ? Num- 

 ber and character of the thoracic appendages ? Does the abdo- 

 men show any signs of segmentation ? Has it any appendages ? 

 Make sketches showing a ventral and a lateral view. 

 Special Organs. 



Examine the head with a hand lens and locate the eyes. 

 Note more particularly the types of appendage found, 

 and the degree of differentiation. Find the openings 

 to the air-sacs on the ventral surface of the abdomen. 

 Locate the spinning glands. Number ? 

 Activities and Habits. — How do the legs act in walking? 

 At what joints are they flexed at various parts of the step? 

 Do all the legs on one side act in unison? Observe the spin- 

 ning action. Does the spider ever produce the threads except 

 when weaving a web? Describe. Determine if possible the 

 kind of web formed by the species studied. Or find as many 

 types of nest or web as possible and learn to recognize the 

 spiders producing them. How does the spider travel on its 

 web? Where do spiders place their webs? Place a living fly 

 or other insect in a newly constructed web and record the 

 actions of the spider. Can you devise means to prove whether 

 the spider possesses the sense of smell ? 



310. The Grasshopper. — Several species of the locusts may 

 be found in almost every locality. They are especially abundant 

 in the early autumn. For laboratory study select the largest 

 species found in sufficient abundance. In connection with the 



