644 Waring ton .— The Effect of Boric Acid and Borax on 
The presence of boron in a large number of plants in nature has been 
frequently described, and in the present instance it has been detected in 
garden-grown broad beans, a larger proportion being present in the pods 
than in the stems or leaves ; Cook ( 16 ), also, has drawn attention to the 
occurrence of boron in plants grown as controls to those on boron-treated 
plots. But in these experiments boron was detected in the dried shoots of 
broad beans grown entirely in ordinary nutrient solution. The question at 
once arose as to the origin of the boron in this case, and also as to why such 
considerable growth was possible before the deficiency made itself evident. 
Three possible sources of boron to the plant grown in water cul¬ 
ture are : 
(1) Atmosphere. 
(2) Nutrient solution. 
( 3 ) Seed - 
(1) The possibility of the plant obtaining boron from the atmosphere 
may be regarded as quite unlikely. 
(2) Qualitative analysis of the nutrient solution showed that it was not 
responsible for any supply of boron. 
(3) The seed, therefore, remained the probable source of the element. 
Accordingly a large number of broad bean seeds, such as had been used for 
the water-culture experiments, were ground up into a fine meal and a chemical 
analysis made, the method used being that described by Bertrand and 
Thomas ( 5 ). The free end of the turmeric paper turned a bright red 
colour, indicating the presence of boron. The reaction was so definite that 
in all probability a comparatively large quantity of boron was present; this 
would explain the great length of time during which healthy growth was 
maintained by the broad bean before the deficiency became apparent. 
h. The Effect of the Removal of the Cotyledons on Subsequent Growth in 
Water Culture. 
Since boron is apparently of such fundamental importance to the broad 
bean plant, it seemed probable that removal of the cotyledons, in themselves 
a source of boron, before growth in water culture, would show up more 
clearly any difference between plants treated with H 3 BOo or supplied with 
the usual nutrient salts only. 
Many authors, from quite early times, have shown that removal of the 
cotyledons or endosperm from the embryo resulted in impaired growth and 
vigour. Both Bonnet ( 9 ) and Sachs ( 32 ) described this in their work on 
Phaseolus multiflorus. More recent work on the subject has been done by 
Andronescu (2) on Zea Mays and Duggar ( 18 ) on Canada field peas and 
field corn. 
Difficulty was experienced at first in growing the dissected out 
plantlets, the method tried at the outset being as follows: the seeds were 
