67 
wrote Sir Joseph Hooker, director 
of the Royal Botanic Gardens at Kew, ‘will be the key which 
With the development 
one of the keys. 
“One of the starting points of Darwin's work,” Sir Joseph con- 
‘Geographical distribution, 
will unlock the mystery of the species.” 
ba 2 
of modern genetics we should now probably say 
tinues, “had been the striking impression made on him by the 
distribution of the Galapagos organisms; hence his eager desire 
to know whether the botany of this isolated group was as sug- 
gestive as the zoology”’ (Life and letters. Vol. I, p. 489) 
Darwin’s statement in his Autobiography was as follows: 
“During the voyage of the Beagle [1831-1836] I had been deeply 
impressed by the South American character of most of the pro- 
ductions of the Galapagos archipelago, and more especially by 
the manner in which they differ slightly on each island of the 
group; none of the islands appearing to be very ancient in a 
ecological sense. It was evident that such facts as these, as 
well as many others, could only be explained by the supposi- 
tion that species gradually become modified ; and the subject 
haunted me.” 
Dr. Svenson sailed for Ecuador from New York on January 30, 
on the S.S. Santa Elena, and returned on April 24. This was the 
twentieth trip, outside the local flora area, for botanical explora- 
tion and study since the Garden was established in 1910. The 
plants collected on this trip, in the form of 
—v 
herbarium specimens, 
are now being studied in comparison with specics collected by 
Dr. Svenson on the Galapagos Islands during the Astor expedi- 
tion, in 1930. 
Chestnut Disease Studtes 
Dr. Graves, with assistants, has continued his studies of the 
destructive fungus disease of the American chestnut, and offers 
(pp. 94-99) a report of progress in the endeavor to bring back the 
chestnut by breeding a tree with lumber-producing trunk and 
‘mmune or resistant to the disease. As we have pointed out in a 
preceding annual report (for 1923), this disease was first dis- 
covered in America in 1904 in the New York Zoological Park. 
It has caused the loss in New York City alone of tens of thousands 
of trees estimated to have had a monetary value of several 
million dollars. In Brooklyn alone a loss of some 17,000 chestnut 
