EXHIBITION MEETING, l9o2 
65 
Jolia L., Gentuina asclepiuded L., Fulyounotam verticiUntuw (F>.) All., 
Hchruchzeria ixilvatris L., Schoenas ferriigineus L., Molinia litorahs 
Host and Lycojjodium mmotimi'rn L. 
F. Rose. 
A MYSTfiRious CABEX ON Ben Lavvers 
An exhibit of herbarium specimens illustrated the article already 
published under the same title in Watsoniu, vol. 2 , pt. 4 , 279-281 (1952). 
Side by side with the first gathering (viz. Sandwith no. 3305) of this 
Ben Lawers sedge were placed sheets of typical Gar ex dioica L., from 
Britain, and others of Scandinavian specimens of the closely related 
G. paralleUi (Laest.) Sommerf. and ('. dioica var. paralleloides Lund 
ex Anderss. 
N. Y. Sandwith. 
The Imi'ortance oe Rhizome Scale Characters in Fern Taxonomy 
E. A. C. L. E. Schelpe. 
Epping Forest Fungi Miss M. Scholey. 
The Creation op New Species through Hybridization resulting from 
Man’s Activity 
Specific rank cannot be logically denied to a fairly uniform true 
breeding popidation having a number of constantly associated mor- 
phological features which distinguish it from related populations of un- 
que.stioned specific rank, even though such a population may have arisen 
through hybridization. Probably many more species of plants have 
arisen in this way than is at present suspected. To establish itself as a 
species, a hybrid must be born into conditions where it can compete 
successfully with other plants and it must develop efficient means of 
reproduction. In a closed natural community hybridization is likely to 
be rare, the number of hybrid individuals few; hence the probability of a 
doubling of chromosomes or the development of agamospermy to offset 
the sterility or reduced fertility often found in hybrids will likewise be 
low. Man, however, during the 8000 years or so that he has cultivated 
plants, has continually destroyed, reduced or disturbed such closed 
vegetational communities; by providing- more and more open habitats 
and permitting hitherto isolated but interfertile species to come to- 
gether, man has probably been a potent factor in the creation of new 
species by hybridization. 
Of such species, the classic example is Spartina toionsendii H. & J. 
droves. The first specimen of this was collected at Hythe on the western 
side of Southampton Water in 1870. It was described as a new species 
in 1881. Since then it has spread quickly over thousands of acres of 
mud flats and established itself on the Continent. This new species is 
now known to have arisen from hybridization between the native British 
Spartina iiiaritima (Curtis) Fern, (chromosome number 2n = 70) and the 
