212 
LIFE, IN ITS INTERMEDIATE FORMS. 
material for future legs as required. “ When the limb is 
thrown off, the blood-vessels and nerve retract, thus leav- 
ing a small cavity in the new-made surface. It is from 
this cavity that tho germ of tho future leg springs. A 
scar forms over the raw surface caused by the separation, 
which afterwards forms a sheath for the young leg.” “ As 
the growth advances, the shape of the new member be- 
comes apparent, and constrictions appear, indicating the 
position of the articulation ; but the whole remains unpro- 
tected by any hard covering until the next change of 
shell, after which it appears in a proper case, being, how- 
ever, still considerably smaller than the corresponding 
claw on the opposite side of the body, although equally 
perfect in all its parts.” 
* Jones’s *' General Outline,” p. 343. 
