LECTURES. 2y 
THE DISPERSION OF SEEDS, 
2x Seprember 29th, H. Burkill, Esq., B.A., 
Keeper of the Herbarium, Cambridge, gave 
a most entertaining lecture upon «The Dis- 
persion of Seeds,” of which the following is 
a resumé :— 
On Leckhampton Hill are two cleared 
patches—one of these has been done for the 
of 1887. When we examine these areas we are struck by the 
different proportions between the various kinds of plants on them, 
and on the neighbouring surfaces ; in one grass is relatively abun- 
dant, in the other it is relatively scarce. We must consider why it 
is so. Well you say it is because just those plants have sprung up 
there and the grass has not had time yet to grow densely. But 
why has not the grass had time to grow dense and matted as yet? 
This is the point in studying dispersion of seeds, for we thereby 
find out how new seeds are carried to new places, and why some 
plants get there before others. 
The first prominent fact in considering this point lies in this 
statement-—Zhat all plants produce more seeds than will eventually 
grow. ‘This is shewn by the following table: 
| No. of Seeds | Total No. of 
Name of Plant. pe each Seeds 
ar) Le 2 Flower. to one Plant, 
Gentiana campestris ... os ae 50 1,000 
Angelica... ye op oe 2 13,200 
*Ceyhalanthera grandiflora (Lady’s Slipper) 6020 24,080 
Plantago major (Plantain) ie : 10 35,500 
Sambucus infra (Elder) : : 3 80,400 
*Orchis maculata (Spotted Orchis) | 6262 186,300 
Betula alba (Birch) ... se Be: I 1,593,600 
#Maxillaria (Foreign Orchids) .-- a 1,750,440 10,538,640 
*Acropera “¢ Bs : 371,280 | 74,000,000 
* From Darwin’s ‘“‘ Fertilization of Orchids.” 
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