214 NATURE STUDY. 



eyes and palps must be related. If we are told that its 

 body is an inch long, we can lay off that distance, or some 

 multiple of it, on the blackboard. Next they might tell 

 that it is about one-third as wide as long, rounded at the 

 sides (oblong, some might say), divided by a neck into 

 two parts, the first a little shorter than the second, both 

 a little longer than wide, rounding toward either end. 

 From such a description we might get a fair mental pic- 

 ture, and make a fair drawing, though we had never 

 seen the spider. Now we want to add the appendages 

 or other parts. It does not help us even now to be told 

 that the spider has eight legs. We cannot relate them 

 to the body. Where are they attached ? we ask. Four 

 fastened on each side of the first division of the body, 

 the first pair back a little from the front end. Now we 

 can place them in our drawing. If next they began 

 to tell about the ends of the legs, we would be at a 

 loss again. The bases of the legs are in place ; the 

 ends have not been related to the base, are off in space. 

 First we must get some idea of the legs as a whole. 

 They are long (an inch long), slender, the first two 

 pairs projecting outward and forward, the last two 

 backward. They taper toward the outer end, and have 

 several (seven) joints. Now we can get and make a 

 picture. When told, not merely that the spider has 

 several eyes, but that the eyes are near the front of the 

 upper surface of the first division, and are arranged in 

 two rows running across, with four eyes in each row, 

 we can draw without difficulty. 



This will serve to illustrate the importance of the 



