THE SENSE-ORGANS 



481 



130, D-F), but three ethmo-turbinalia are usually represented, 

 and these are of the simplest character. Of these the two 

 largest, II and III, form the " upper and middle concha " of 

 human anatomy. The first, I, is a rudiment, and the last. 



FIG. 130. Diagrams of ethmoturbinals in Mammals. [After PAULLL] 



(A) Type showing endoturbinalia alone. (B) Type with endoturbinalia (heavy 

 lines) and two ranks of ectoturbinalia. (C) Diagram of turbinals and pneumatic 

 cavities in the ox. (D), (E), (F) Diagrams of three actual cases in man, showing 

 individual variation. 



IV, is usually absent. The " lower concha " is a distinct bone, 

 the maxillo-turbinal, and is not shown in the diagrams. In the 

 human embryo a larger number of ethmo-turbinals occurs, 

 showing that man's immediate predecessors possessed a much 



