PRESIDENTIAL ADDRESS. 489 
there are no mutations there can be no evolution.’ The disagreement about 
the way in which evolution has proceeded has perhaps arisen from a mis- 
understanding as to the nature of the two kinds of variation described 
respectively as mutations and fluctuations. Mutations are variations 
arising in the germ-cells and due to causes of which we are wholly ignorant ; 
fluctuations are variaticns arising in the body or ‘soma’ owing to the action 
of external conditions. The former are undoubtedly inherited, the latter 
are very probably not. But since mutations (using the word in this sense) 
may be small and may appear similar in character to fluctuations, it is 
not always possible to separate the two things by inspection alone. The 
whole matter is well illustrated by the work of Johannsen on beans. He 
found that while the beans borne by any one plant vary largely in size, 
yet if a large and a small bean from the same plant are sown, the mean 
size and variability of the beans on the plants so produced will be the same. 
The differences in size are presumably due to differences of condition and 
are not inherited. But if two beans are sown, one from a plant with 
beans of large average size, and one from a bean of small average size, the 
bean plant whose parent had the high average will bear larger beans than 
the one from the parent with small average beans. The faculty of pro- 
ducing a high or low mean size is congenital, is a mutation in the sense 
used above, and is inherited. It is no doubt unfortunate that the word 
mutation has been used in several different senses, for it seems to have led 
to most regrettable confusion and misunderstanding. 
As I have said, in such a year, and in my position, I ought perhaps 
to have devoted the whole of this address to the more philosophical side of 
our subject; but, in truth, I am no philosopher, and I can only say, as 
Mr. Oliver Edwards, ‘an old fellow-collegian’ of Dr. Johnson’s said to 
the ‘great lexicographer’ when they met after nearly half a century of 
separation: ‘I have tried too in my time to be a philosopher, but I don’t 
know how, cheerfulness was always breaking in.’ 
II. 
Organising Zoology. 
I now turn to a subject of the greatest moment and of the greatest 
difficulty, and one on which there is little general consensus of opinion. 
The question I wish to raise is this—are the zoologists of the world setting 
about their task in an economic and efficient way? 
We live surrounded by a disappearing fauna. Species are disappearing 
from the globe at a greater rate than even the most ardent mutationist 
claims they are appearing. To mention but a few striking cases: The 
European beaver has almost gone, though a few linger on around the 
periphery of the Continent. Norway, the lower Danube, Eastern and 
Arctic Russia still harbour them, and a very few are said still to inhabit 
the Rhine and the Rhone. The European bison is now represented by a 
few wild specimens in the Caucasus. The American bison is reduced, and 
that by the deliberate and calculated action of man, to a few herds most 
carefully preserved by Government; the largest of these, containing some 
600 heads, is now at the National Park at Wainwright. Equally de- 
liberate and equally calculated is the destruction of the fur-seal which 
threatens soon to be complete. The Greenland sealing is almost a thing 
of the past. In 1860 British vessels killed 68,278 seals ; in 1866, 103,758 ; and 
this went on until 1895, when the pursuit was abandoned by the British, 
it being no longer found to pay them, though Norwegians still continue 
