the Broad Bean and certain other Plants. 
645 
soaked in water overnight, and the plumule and radicle dissected out the 
next morning and placed on a porous pot standing in nutrient solution. 
Slight growth was made, but all died after a few days. The use of 
a nutrient solution with the addition of organic matter such as glucose or 
mannite gave rather better results, but fungal and bacterial growth made 
this method unsuitable. 
Finally, it was decided to allow germination to start in damp saw r dust 
and not to attempt to grow the young plants until the radicle was about an 
inch long. At this stage the plumule was in most cases quite yellow, but 
had sometimes turned green. It was found almost impossible to obtain 
seedlings uniform in their development, but care was taken to put the 
strongest of them in the control solution, so that any error thus introduced 
should be in favour of those deprived of boric acid. Eight of these de- 
cotyledoned seedlings were set up in ordinary nutrient solution, four of 
which received in addition 1 : 50,000 H 3 B 0 3 . As a further contrast a seed¬ 
ling still retaining its cotyledons was set up in each kind of solution. 
From the first the seedlings which had been divested of their cotyledons 
fell very much behind the untreated plants, and they never attained anything 
approaching normal development. Growth was so slow that even after 
twenty days in the solution only a few laterals had been developed, and 
after forty-two days there was but little difference to be seen between those 
supplied with H 3 B 0 3 and the control plants. However, a week later, when 
some of the plants were beginning to flower, the controls fell behind, and in 
some cases signs of ‘dying off’ were evident. In time, all the plants 
deprived of boric acid showed this phenomenon, but in no case was therg the 
slightest indication of withering among those supplied with boric acid, either 
in the untreated or de-cotyledoned plants. 
Qualitative analyses of soaked or germinated seeds showed that not 
only the cotyledons but also the plumule and radicle contained a relatively 
large proportion of boron. Removal of the cotyledons did not, therefore, 
completely deprive the plantlets of the element, and this would account for 
the considerable growth made by the untreated plants. Some food materials 
also would have been absorbed by the plantlets from the cotyledons during 
germination, and it is possible that a transference of boron took place at the 
same time, thus further augmenting the supply. It is also probable that, 
under these conditions of extremely slow growth, a quantity of boron which 
under ordinary circumstances would have been entirely inadequate for so 
long a period, was sufficient to meet the demands of the plant. 
B. Barley. 
In 1914 Brenchley (11 (a)) described a series of water-culture experi¬ 
ments on the action of boric acid on barley. The present investigation was 
carried out on somewhat similar lines to obtain a comparison both with the 
