XVI 11 



Blood-purifying and Sound-producing Organs. 



IYI. RESPIRATORY SYSTEM. 



N. SOUND-PRODUCING ORGANS. (Including Larynx 

 and Syrinx.) 



O. URINARY ORGANS. (Including Kidneys, Bladder, 

 and Waste-Products.) 



P. SPECIALIZATION AND DIVISION OF LABOUR 

 AMONGST "PERSONS" OR "INDIVIDUALS." 



STRUCTURES CONCERNED IN THE PRE- 

 SERVATION OF THE RACE. 



Q. REPRODUCTIVE SYSTEM. 



R. STRUCTURES FOR THE PROTECTION OF THE 

 YOUNG. (Including Eggs, Egg-Capsules, Nests.) 



S. STRUCTURES CONCERNED IN THE NOURISH- 

 MENT OF THE YOUNG. (Including Mammary 

 Glands and Placentae.) 



T. DEVELOPMENT. 



U. ALTERNATION OF GENERATION. DIMORPH- 

 ISM. POLYMORPHISM. 



V. SECONDARY SEXUAL CHARACTERS. 



W. NORMAL VARIATIONS OF SPECIES. 



X. ASSOCIATION OF DIFFERENT SPECIES, WITH 

 OR WITHOUT MODIFICATIONS OF STRUC- 

 TURE. 



