144 
H. H. W. PEARSON, F.R.S., Sc.D. 
phytogeographical questions suggested by the different types of vegetation 
and the varied physical conditions of the countries through which he travelled. 
Had Pearson lived a few years longer there is no doubt he would have worked 
up his field-notes into a connected whole, and knowing how well qualified he 
was by training and by his ability to see things in their true perspective, one 
is able to realise to some extent how valuable such a digest of his knowledge 
and mature experience would have been. His thorough treatment of the 
problems presented by the root-parasite Striga lutea, a Scrophulariaceous 
plant locally known as the Rooibloem or Witchweed, which causes serious 
loss to cultivators of Maize, and the valuable practical directions for dealing 
with the disease afford further evidence of his versatility and of his desire to : 
demonstrate the importance of botany as an applied science. With the 
assistance of Miss Stephens, one of his pupils, he studied the details of the 
haustorial structures and their connexion with the host ; he also investigated 
the germination and dispersal of the small seeds and made many experimental 
trials of different methods of dealing with the pest. Previous attempts to 
germinate the seeds of Striga had been unsuccessful and Pearson proved that 
germination occurs only in presence of the host. 
During a halt in Namaqualand Pearson made observations on the internal 
temperature of Euphorbia virosa and Aloe dichotoma. He found that 
Euphorbia, with its large chambered pith, responds more quickly than the 
Aloe to changes in the external temperature and attains higher maxima. 
He also investigated the effects of wounding: in Aloe the lowering of the 
internal temperature is due to evaporation at the surface of water conducted 
through the xylem, while in Euphorbia the lowering is due in part to surface- 
evaporation but also to the expansion of gases imprisoned in the pith. 
In answer to a request for a few words about our friend the High Com- 
missioner in London for British South Africa, the Rt. Hon. W. P. Schreiner, 
wrote as follows : “ I don’t think that I can really add anything that is not 
better said by others about dear Pearson. I entirely associate myself with 
what is written of him in prose and poetry in an article in the South African 
College Magazine for November, 1916, where he is placed at the front of the 
Roll of Honour. My abiding impression of him is of a shining bright per- 
sonality. His laugh was a tonic. He was the most cheery man at cheerful 
gatherings such as our remote Oxford and Cambridge dinners on Boat Race 
night, or at the Annual College feasts at Cape Town. But his work and 
purpose were never lost sight of, and he won his way not only to our hearts 
but also to our pockets for the big object which he accomplished. He was 
a boy among men, but a greatly respected man among his boys and girls at 
College. By none more than by his friends and students in South Africa is 
his loss deplored.” 
Harold Pearson was a high-minded student and loyal citizen whose short 
