152 



BOYS AND GIRLS IN BIOLOGY. 



old folks at home. Of course, as he grows his shell 

 gets too small, but, instead of putting on an addition as 

 the mussel does, he leaves the old house altogether and 

 builds a new one. How he ever extricates himself from 

 all the numerous extensions and divisions of his dwell- 

 ing is indeed a mystery, and how he can possibly build 

 a new house in so short a time as he does is another 

 mystery. In three days after the lobster moves out of 

 the old house, he has been found settled in a bran-new 

 one, one-third larger. He is about as swift a worker as 

 the red and green snow-carpenters we found in the arc- 

 tic and Alpine regions. When the lobster's shell be- 

 gins to pinch, it makes him feel very uncomfortable and 

 bilious-like ; at least he does not care to go into society, 

 lest he should become unnecessarily exposed to the 

 rude gaze of the unfeeling crowd. So he retires by 

 himself to a quiet place, fastens his feet to some 

 firm body, and moves himself about till he has broken 

 the last tie that binds him to the old home ; then the 

 walls begin to crack between the shell of the head — the 

 carapace — and the shell of the body — the abdomen. 

 Now the lobster pulls himself slowly backward till his 

 eyes are fairly through the crack, then he gives one 

 jump backward, and leaves the whole thing at a single 

 bound. The old habitation, with every apartment com- 

 plete, even to the very teeth in the old mill, remains 



