THE GUSTATORY APPARATUS. 



187 



secondary taste center, and a third along the surface of the mid- and hindbrain 

 neuromeres, probably terminating around the motor neurites at the base of each 

 pedal ganglion. 



Olfactory 

 Coordination 



Bea-or'ter. Cent, 

 olf. VIS. gu«t. 

 locoTn. sw/im. 

 respir 



Visual 

 Swallowing 



tKt. 



7 



Fig. 1 14. — ^Diagram of the brain of Limulus, showing the course of the principal nerve impulses, and the loca- 

 tion of the principal centers of control. The figure is constructed from the data obtained by experimental and ana- 

 tomical methods. Only the first and fourth thoracic, and the first branchial appendage on the right side of the 

 animal are shown. The most important points illustrated are (a) the primary, g.c^., secondary, g.c.^, and tertiary, 

 g.c}, gustatory centers; (b) the relation of the motor, sensory, and association neurones to the muscles used in the 

 chewing reflexes; (c) the crossed thoracic temperature impulses; and (d) the crossing of the branchio-thoracic im- 

 pulses in the vagus neuromeres. The lettering of the neurones is the same as that in Figs. 56 to 66. 



Closely associated with the secondary taste center is the " swallowing center," 

 or the lateral stomodasal ganglion, si.g.^ lying on the median margins of the cheli- 

 ceral neuromere, next to the walls of the stomodseum. It is connected with its 

 mate by a special pre-oral commissure, six. 



