574 SCIENCE IN AFRICA 



adulterated sour milk and a soup made from leaves of the baobab 

 (kuka) tree, which analysis shows to have a peculiarly high calcium 

 content. Groundnut oil and meat are daily additions for rich 

 people, but are rarely eaten by the general population. He con- 

 siders that the failure of a dietary in quality rather than quantity 

 may easily be overlooked because of the erroneous idea that 

 specific deficiency in diet must be observable in the form of special 

 diseases. In actual fact the majority of specific deficiencies result 

 in a general lowering of vitality and resistance to disease, as origin- 

 ally pointed out by Sir Robert McCarrison (192 1). 



Among the Hausa of Nigeria the low birth rate is attributed to 

 infertility among the women. This suggested a general deficiency 

 in vitamin E, and in order to put it to proof, exhaustive experi- 

 ments have been made at the Katsina laboratory by feeding rats 

 with typical native foods : almost invariably a reduction in fertility 

 has resulted, but it seems that these results on fertility are not 

 conclusive, since changes in diet, other than those resulting in 

 deficiency, may eflfect the fertility of captive rats. McGulloch 

 attaches importance to calcium deficiency in relation to fertility, 

 and points out that certain villages which are well known among 

 natives for their fertile women are those where the kuka trees 

 grow in profusion. The poor quality milk is likewise attributed 

 to calcium deficiency, and it is suggested that the long period 

 (two or three years) of lactation is an adaptation to give the child 

 a certain modicum of this element. It is interesting to note that 

 McGulloch's figures for growth-rate show an abrupt arrest after 

 puberty, and in this respect are similar to the figures recently 

 collected by Dr. Gordon in Kenya {see pages 584-6). In general 

 the West African tribes considered may be said to suffer diet 

 deficiencies in vitamin B, vitamin E, calcium, iron, iodine, and 

 protein. 



Since the publication of these results, biochemists have been 

 added to the scientific staff of medical departments in order to 

 carry out among other duties, the analysis of local food materials. 

 Among investigations, the results of which are published, may be 

 mentioned that carried out in Zanzibar by Harden Smith (1935) 

 and a nutritional review of the natives of Zanzibar (1937), which 

 is one of the first fruits of the Golonial Office circular mentioned 



