140 Transactions of the Royal Society of South Africa. 
Bowenia, a remarkable Australian Cycad, and even at that time it is clear 
that many problems relating to the physiology and oecology of the Cycads 
must have been prominent in his mind. This was Pearson's first piece of 
research work at Cambridge and it is interesting to note that he never 
forsook this group, which had for him a peculiar fascination. 
His account of the botany of the Ceylon Patanas is of exceptional 
interest to the South African botanist in that the flora of the Patanas bears 
in many respects a striking resemblance to that of the High Yeld in South 
Africa, and one regrets that other duties and strenuous work .prevented 
Pearson from pursuing the oecological studies begun in Ceylon further with 
respect to the grassland of this country, especially as the same problems 
and questions that presented themselves in Ceylon must have occurred again 
and again to him here. 
His study of the Patana vegetation aroused an interest in Xerophytes, 
which he retained to the end. In particular, he drew attention to the 
absence of plants with bulbs or tubers from the flora of the dry Patanas, 
and in this respect it must have formed a striking contrast to that which 
he encountered in his travels in South Africa. 
While at Kew Pearson was engaged chiefly in systematic botany, but 
he also undertook a morphological study of the double pitchers found in 
certain members of the genus Bischidia, and from his examination of dried 
and scanty material he put forward the novel theory that the double pitchers 
represented Xerophytic characters. His systematic work included the 
working up of the Verbenaceae for the ' Flora Capensis.' 
Coming to South Africa in 1903, Pearson's first botanical publications 
dealt with the Verl)enaceae, and very soon afterwards he published an 
instructive and useful paper on the South African Cycads. 
At an early date he turned his attention to the study of the flora of 
South -West Africa, where he travelled and explored the desert regions 
inhabited by WelwitscJda and other no less remarkal)le Xerophytes. His 
observations on Welwitschia were not confined to the field, but were supple- 
mented by a series of classical papers detailing the results of anatomical 
and histological studies. He first made himself thoroughly familiar with 
the natural history of the plant, journeying to Damaraland on no less than 
three occasions solely with the object of studying it in the field. 
As a result of these observations he concluded that full-grown plants 
reached an age of considerably over a hundred years, that they were 
pollinated by insects, and that when growing in contact they frequently 
formed natural grafts. The material which was acquired on these different 
expeditions formed the basis for a most exhaustive study in his laboratory 
at Cape Town of the details connected with the process of fertilisation in 
Welwitschia, and conclusions of extraordinary interest relating to the 
organisation and structure of the endosperm were put forward by Pearson. 
