PRESIDENTIAL ADDRESS — FERGUSSON. Cxix 



The rediscovery of Mendel's work in 1900 gave an impetus 

 to scientific breeding experiments with animals and with plants 

 Results of economic importance and scientific value have 

 followed. Cambridge has given the English farmer cereals 

 increased in strength and yield and immune to rust, heredi- 

 tary qualities capable of being transmitted in accordance with 

 Mendel's law of segregation. As the chemist now looks to the 

 physicist for the constitution of his unit, the atom; so the 

 biologist appeals for the exploration of his unit, the cell, to the 

 biochemist. With the union of gametes we have the cell in 

 which the problem of heredity is wrapped up; and as Dr. 

 Schafer has said, we must not be blind to the possibility that 

 these transmitted qualities may be connected with specific 

 chemical characters of the transmitted elements: in other 

 words, that heredity is one of the questions the eventual 

 solution of which we must look to the chemist to provide. 



Miss Wheldale has recently done work on the coloring 

 of flowers, finding chromogens supposedly derived from gluc- 

 osides by hydrolysis, in which the color is developed by 

 enzyme oxidases and peroxidases. White flowers may be "of 

 two kinds, one in which chromogens are absent and the other 

 in which they are present, but unacted on by the enzymes. 

 Prof. Keeble and Dr. Armstrong have investigated this subject 

 and developed chemical tests to distinguish the two kinds of 

 white flowers, to do which previously, breeding experiments 

 would have been required. The significance of this is, that 

 here we have the beginning of the chemists' work on heredity, 

 color being a Mendelian unit-character. 



Examination of the bacterial content of soils has shown 

 their intimate connection with plant growth, and the parts 

 played by some of these organisms have been worked out. Re- 

 cent work on partial sterilisation of soils, after which the 

 bacterial growth is much enlarged with consequent increase 

 in crops suggests the destruction of protozoan enemies of the- 

 bacteria as the cause of increased bacterial content. 



