PHYSICAL CHARACTERS IN MAN 41 



suited from a similar mutation, although here the back 

 is long, as also in the turnspit. A variety like the 

 turnspit, having crooked legs and a long back, was 

 formerly known among the pariah dogs of India. 



To quote some of the further conclusions of Daven- 

 port regarding heredity of stature in man, he finds 

 that the time of onset of puberty is probabh' an ele- 

 ment in determining the stature ultimately reached 

 by the individual, and that the factors for tallness 

 are mostly recessive — probabl}^ due to the absence 

 of inhibitions to prolonged growth. The least vari- 

 able offspring are, therefore, the children of two tall 

 parents, all being usuall}^ tall, while tall mated with 

 short will give the most variable result owing to the 

 recessive factors for greater stature carried b}^ the 

 short parent. 



An interesting experimental result bearing on the 

 subject of gigantism has recentty been obtained 

 by Uhlenhuth (192 1). He fed young salamanders 

 {Ambly stoma) on a pure diet of the anterior lobe of 

 the M'pophysis (pituitary*) of cattle, control animals 

 being fed with earthworms. A greath' increased 

 rate of growth resulted, and when the normal adult 

 size was reached growth continued at a decreasing 

 rate, until animals of gigantic size w^ere produced. 

 The hormonef from the anterior lobe of the hypophysis 

 not onl}^ accelerates growth, but also maintains 

 growth after the normal adult size is reached. Carrel 

 finds that in tissue cultures the growth of the cells 

 of warm-blooded animals is not accelerated by hypo- 

 physis extract, and various investigators have shown 



* The pituitary is a small reddish ellipsoid organ in a depression 

 (the sella turcica) at the base of the skull. It consists of anterior 

 and posterior lobes. 



t A hormone is a chemical substance produced as an internal 

 secretion in a gland or organ and carried in the blood-stream in 

 minute quantities to control the activity of another organ. 



