142 Transactions of the Royal Society of South Africa. 
parison in the herbarium, but he set himself to inquire in the field into 
certain definite physiological phenomena connected with the internal 
temperatures of plants growing under desert conditions. Observations 
made in December on Ewpliorhia virosa^ and Aloe clichotoma revealed the 
fact that the internal temperature of the former rose as high as 51*5° C. 
Eu])lior})ia^ also showed an excess of internal temperature over that of shade 
by 15*35° C, while Aloe did not vary more than 5° C. He further made 
the interesting observation that when wounded a considerable drop in 
internal temperature took place in Eu])horhia ; this, Pearson explained, was 
partly due to evaporation at the wound and partly to the expansion of 
gas in the air chambers. 
In addition to his more purely scientific work Pearson also undertook 
an investigation of the " Witchweed," a phanerogamic parasite which was 
causing damage to maize crops in the Transvaal. The botanical characters 
of the parasite were soon worked out with a skill and clearness of vision 
that were characteristic of the man, but through no fault of his no practical 
solution to the problem was arrived at. 
As a lecturer Pearson had that rare gift of ready and lucid exposition. 
He thought quickly and clearly. He took an active though unobtrusive 
part in the affairs of the Cape of Good Hope University, and latterly was 
much absorbed in the selection of the site of the University of Cape Town 
on the Groot Schuur Estate and its future relationship to the National 
Botanic Gardens. 
To the South African public Pearson was best known as the Director of 
the National Gardens at Kirstenbosch, which ofiice he filled in an honorary 
capacity, and nothing pleased him more when opportunity arose than to 
show both local and distant visitors the work that was then in hand at the 
Gardens and discuss plans and possibilities for the future, always both 
humorous and courteous to all alike. 
By Pearson's untimely death the Royal Societies of both London and 
South Africa have been robbed of a Fellow whose name will always rank 
with those of Thunberg, Burchell, Ecklon, Zeyher, Drcge, and Bolus, whether 
he be regarded as a naturalist, botanist, traveller, explorer, or teacher. 
He is lamented by all who knew him, and it is difficult to contemplate 
Cape Town and the National Gardens without his cheery and enlivening 
presence. Ill could the country afford to lose him. I. B. P. E. 
LIST OF PAPEES. 
1898. "Anatomy of the Seedling of Bowenia S2^ectahilis,''^ Hook, f. ('Ann. 
Bot.,' xii, pp. 475-490, tt. 27-28). 
1898. " Apogeotropic Roots of Bowenia spectahilis,'" Hook, f . (' Rep. Brit. 
Assoc. Adv. Sci.,' p. 1066). 
