138 



BOYS AND GIRLS IN BIOLOGY. 



by a tube at the side of the feelers (antennae) toward 

 the mouth. A bristle passed through the opening will 

 enter the " green gland." It has been quite a puzzle 

 to know the use of these glands ; at first they were sup- 

 posed to be the lobster's ears. Next we will take a look 

 into the side-chambers of the head and breast (cephalo- 

 thorax) and see what the three pair of walking-legs, 

 the great pincers, or chelje, and the two pair of jaw- 

 feet, are doing in there. In each chamber we find eigh- 

 teen little tapering, feathery-like bodies (Figs. 120, 121). 



Fig. 121. 

 Tergum, or Back-shell. Heart. 



P 



Nerve bunch, or Ganglion. 

 Cut, or Section, op Lobster, showing the Position of Heart, Stomach, the 

 Chain of Nerves, and Gills. 



Each has a central stem surrounded by fine, feathery 

 filaments ; they look very much like so many little bot- 



