Obituary . — Henry Harold Welch Pearson . ix 
ing to its author’s definition) and applies equally to the prothallus of Pines 
and to this endosperm of Welwitschia and the Angiosperm, I want a morpho- 
logical name for my new organism. I propose to call it the Trophophyte.’ 
The Welwitschia work naturally led to an attack on Gnetum , and one 
of the main objects of the Expedition of 1908-9 was to obtain material of 
Gnetum africamim from Angola. The first part of this journey was made in 
company with the Magnetic. Survey Expedition of the Carnegie Institute, 
under the leadership of his close friend and colleague, Dr. J. C. Beattie. 
On April 12, 1910, he wrote: ‘I have both Gnetum africanum and 
G. scandens on the go, and I have cut about ten ovules of each. . . . While 
I am not yet able to prove it to the satisfaction of a sceptic I have myself 
no doubt that the endosperm [ Gnetum] is formed as in Welwitschia (the 
attitude is, I am afraid, unscientific, but it is I think impossible to keep one’s 
mind open until the proof is complete).’ In November, 1915, he added: 
‘ I have at last settled the question of the resemblance of the endosperm [of 
Gnetum] to that of Welwitschia ; it is formed in exactly the same way, 
which pleases me mightily.’ 
Prof. Pearson consented to contribute a volume on the Gnetales to the 
‘ Cambridge Handbooks’, edited by Mr. Tansley and myself, and this work 
may, we hope, be far enough advanced to be published. In a letter dated 
April 20, 1916, he wrote: ‘A large part of the book on the Gnetales is 
written, though it will need some revision. . . . As to the Gnetalean- 
Angiosperm alliance, there must be one, I think, but at present I cannot bring 
myself to believe that it is direct. If they are not connected that endosperm 
wants a lot of explaining. The trouble is that I cannot make head or tail 
of the flower, and the relation between Ephedra and the others is extremely 
puzzling. The latter is probably very simple if we only had the key — the 
former I dream about, so far unsuccessfully. As to Bennettites , I think 
I made far too much of the idea of a relationship in 1909, but I have not 
given it up yet. The more we know about the group the more difficult it 
seems to become.’ In a later letter he made an interesting suggestion about 
the comparison of the Gnetales and the Bennettitales. ‘ I am bothered by 
my ignorance of Bennettites. I have never seen a section of a flower and 
the idea I have been harbouring for some time is very probably absurd. It 
is about that interseminal scale, the real nature of which, so far as I can make 
out, no one seems to understand. In my ignorance I have wondered whether 
it is really a “ scale ” at all.’ He suggests that the interseminal scale ‘ may be 
something of the nature of the thick cushion of Gnetum . ... If you have 
a large number of ovules arising in crowded whorls or spirals from an 
elongated conical axis, and sunk in the tissue of the axis, as are the young 
ovules of Gnetum africanum , it seems to me that transverse and longi- 
tudinal sections might give very much the appearance of such sections 
of Bennettites l 
