484 The Outline of Science 



How can it be entailed on the male offspring only? The answer 

 must be that the quality is handed on to both sexes, but that it 

 cannot find expression except in a male constitution. Similarly, 

 the foundations of milk-glands are part of the inheritance of both 

 sexes, but normally their development is restricted to the females. 

 There are items in the inheritance of both sexes which are like 

 seeds requiring particular kinds of soil if they are to develop. 

 The male character of antlers or of shaggy mane requires a mas- 

 culine constitution (including the presence or absence of certain 

 hormones) if it is to develop. This leads to the view that the 

 secondary sex characters are in their origin bound up with the 

 primary differences of constitution implied in maleness (sperm- 

 producing) and femaleness (egg-producing) respectively. 



All theory apart, we return to the facts : ( 1 ) that the male 

 mammal is often markedly different from his mate, (2) that there 

 are often fierce combats between rival males, and (3) that in 

 certain cases the females seem to show a certain preference, being 

 apparently more excited by some males than by others. It is 

 probably the total get-up that counts rather than any individual 

 item such as an extra long beard. The combats of rival stags are 

 sometimes furious, and the antlers are occasionally interlocked 

 with fatal results to both combatants. A male antelope some- 

 times punishes an upstart youngster so severely that the blood 

 flows from many wounds 



14 

 Family Life 



Some mammals are monogamous, others polygamous, and 

 others promiscuous. The monogamous forms include the 

 Chimpanzee, the Tarsius Spectre, the Hedgehog, the Elephant 

 Shrew (Rhynchocyon) , the Pangolin, some antelopes and small 

 deer, and the Bandicoot (Perameles obesula). The polygamous 

 forms include most deer and antelopes, wild cattle and horses, 

 sea-lions, and elephants. Not infrequently the males live by 



