Means of Dispersal. 29 
peat-bogs that are within a mile of an Oak-tree. They 
are common also in some places on the top of the escarp- 
ment of the South Downs, half a mile from Oaks, and 300 
or 400 feet above them. They are always associated with 
empty acorn-husks, stabbed and torn in a peculiar way. 
In October and November rooks feed in the Oak-trees, and 
I have long felt convinced that they were mainly responsible 
for the dispersal of acorns. On October 29th of 1895, in 
the middle of an extensive field, bordered by an oak-copse 
and scattered trees, I saw a flock of rooks feeding and 
passing singly backwards and forwards to the Oaks. On 
‘driving the birds away, and walking to the middle of the 
field, I found hundreds of empty acorn-husks, and a 
number of half-eaten pecked acorns. It was noticeable 
that many of them were not shed acorns, but were accom- 
panied by acorn-cups, the stalks of which had been bitten 
to tear them off the tree. The reason for the selection of 
acorns in cups is probably that they are easier to carry —a 
shed acorn must be an awkwardly large and slippery thing 
for a rook’s beak, one with a stalk will be more convenient. 
Several uninjured acorns were found, one, almost uninjured, 
had been driven by a single peck deep into the soft soil of 
a mole-hill. 
In this way oak-woods must spread rapidly ; but we 
still want observations as to the extreme distance to which 
acorns are thus carried. I have seen seedling Oaks at a 
distance of a mile from the nearest tree (not necessarily the 
tree from which the acorn came) and have found the 
characteristically torn husks somewhat further away.* 
Mr. J. J. Armistead, moreover, recordst that he once 
found a young Oak in a sheltered ravine among sea-cliffs 
on the northern coast of Hoy, Orkney. The tree was 
* Nature, No. 1358, vol. liii., p. 6 (1895). 
+ Zoologist, p. 19 (1891). 
