THE IMPERFECTIONS OF MAN 



with anything except the unquahfied incubus of transfusion 

 accidents and haemolytic disease. 



It is possible, then, as Haldane has suggested, that the 

 diversity of Rh blood types represents a second kind of poly- 

 morphism — that which is merely transient, a necessary inter- 

 mediate stage betv/een the elimination of one type or the other. 

 This interpretation is borne out by the existence of rather bold 

 inequalities among different races and nations in the propor- 

 tions which belong to the several groups. The number of 

 Basques who are Rh-negative falls between one in three and 

 one in four, but Levine and Wong found only one Rh-negative 

 individual among 150 Chinese, having been led to their 

 enquiry by the significant observation that haemolytic disease 

 in China is very rare. If the interpretation is true, then haemo- 

 lytic disease could be explained away as a transient genetic 

 ailment of mankind, but fortunately we can look forward to 

 something a little more expeditious than an evolutionary cure. 



Man''s upright carriage may be a constant source of moral 

 satisfaction, but it has certain serious mechanical drawbacks. 

 Man is unique among four-legged animals in being able to 

 stand erect, on the flat of his feet, and to balance himself in 

 that position. (Even gorillas do not stand upright more than 

 momentarily, and they walk not on the flats but upon the 

 outer margins of their feet.) The shape of the backbone has 

 changed accordingly. In all other animals, with unimportant 

 exceptions, the backbone is more nearly horizontal than vertical, 

 and it takes the form of a single unkinked or uninflected arc 

 from neck to tail. The ''vertebral column"* is not a column at 

 all, but is more like a cantilever having the four legs as piers. 

 The vertebral column of a human being is no longer a simple 

 uninflected arc; it bends slightly forwards in the neck, slightly 

 backwards in the thoracic cage; forwards again in the lumbar 



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