OBSERVATIONAL LESSON IV 



PART I A SEED-POD (continued, ^th investigation) 

 PREPARATIONS FOR WORK 



The dwarf bean plants will again be required. 



DIRECTIONS TO THE PUPIL 



(1) Make and record your fourth series of observations upon the 

 chosen seed-pod, which if necessary may be the last. (See lessons 



MIL) 



PART II THE SUN (continued) 

 Note :- 



(2) If at the beginning or end of this and subsequent lessons the 

 sun affords an opportunity of continuing the records begun in 

 Lesson II, part I (page 20), advantage should be taken of it. 



PART III A CRAB 

 PREPARATIONS FOR WORK 



kBHH 



Each student should be provided 

 with a small living shore crab or an 

 edible crab (see page 146) and a straight- 

 sided dish of no great depth. 



Note : If a large crab is chosen, it 

 may be necessary to tie each of its claws, 

 in order to guard against accidents. 

 The small swimming crab in which the 

 last pair of " legs " is converted into 

 paddles offers some slight variation, but 

 it can often be caught in nets in very 

 large numbers. An advantage in con- 

 nection with this species is that it cannot move so rapidly as many others do 

 when on dry land and can therefore be examined more easily. 



41 



From a photograph by Wilfred Mark Webb. 



FIGURE 40. The back of an ordinary edible crab. 



