The Dispersal of Fruits and Seeds by Ants. 27 
insect life is more abundant than in Sweden. It is clear from a 
perusal of Sernander’s monograph that too little attention has been 
paid to this interesting method of plant dispersal and that a closer 
study of this feature of plant life may explain some of the problems 
which still puzzle ecologists. 
One such problem, first mentioned to me by Mr. Tansley, and 
to which Mr. Hugh Richardson of York subsequently drew my 
attention, was the apparent incursion of furze bushes into pure 
heather moor. A striking example of this is seen on the high 
moorland between Rievaulx Abbey and Coxwold particularly in the 
region just above Wass bank. Here numerous bushes of Ulex are 
found on either side of the main road, and also, diverging from the 
main road, long rows of furze bushes may be seen running a quarter 
of a mile or so into the Calluna moor. A closer examination shows 
that these rows of furze bushes mark the course of old cart tracks, 
the ruts of which can still be seen under the heather, particularly 
where the heather has been burnt off. As the seeds of the furze 
are provided with a bright orange caruncle containing a large amount 
of oil (Text-fig. 2) and resembling therefore the elaiosomes of the 
B 
A 
Text-fig. 2. Seed of Ulex Europaeus (enlarged about ten times) showing 
caruncle. A., Side view. B., View looking down upon hilum. 
mymecochorous plants, it appears to me that the intrusion of the 
furze into the heather-moor may be due to the dispersal of the 
furze-seeds by ants. Ants are known to make use of paths and 
tracks across a country otherwise difficult to negotiate and they 
might well have made use of the ruts of the old cart track. As a 
matter of fact I found ants, and even a small nest, in one of the 
old ruts in which seedlings of Ulex were also found. Unfortunately 
I was unable to make investigations on the spot as to an actual 
dispersal of the Ulex seeds by ants. Experiments made with ants 
in captivity have not been very conclusive, for though in some 
cases they carried away and buried the seeds provided for them, 
they often left them untouched. However they also neglected the 
