Apri 18, 1907 | 
NATURE 
SD: 
instructed writers in the lay Press, according to whom 
natural selection is nothing but a discarded fashion 
of the mid-Victorian period, as obsolete to-day as the 
pork-pie hat and the crinoline. But he is none the 
less a disbeliever in the Darwinian account of the 
origin of species. 
High as are the merits of Mr. Lock as an ex- 
positor, there are points, as we think, on which his 
arguments must fail to carry conviction. The pheno- 
mena of adaptation we hold to be of supreme import- 
ance in the interpretation of evolutionary process. It 
is difficult to exaggerate the extent to which adjust- 
ment to the circumstances of life prevails in every 
department of organised nature. This is a fact 
which the advocates of ‘‘ mutation’’ do not fairly 
face. Mr. Lock is too candid not to admit that 
“ organic beings on the whole are, as a general rule, 
very closely fitted for the conditions in which they 
have to pass their lives.”’ But after adducing certain 
well-known instances of ‘‘animals having peculiar 
habits, and possessing at the same time special 
organs which render them well fitted for these habits 
and no others,’’ he manages to convey the impression 
that such cases are not very common, and that, con- 
sidered as evidence of the power of natural selection, 
the best of them are open to criticism. Then, after 
a sketch of the theories of mimicry and protective 
resemblance, he adds that it is ‘‘ uncertain whether 
this principle [of natural selection] can hold good as 
the true description of the origin of any sort of re- 
semblance. ”’ 
“Perhaps a still more serious criticism,’’ he goes 
on to say, ‘‘of the methods of those who spend their 
time in seeking out or devising cases of adaptation 
has been made by Bateson, who points out the logical 
difficulty that we can never make any quantitative 
estimate of the amount of benefit or the reverse 
which any particular structure may afford to its 
possessor.’? Most biologists will allow that quanti- 
tative methods should be used wherever possible for 
the solution of the problem, and it is curious that Mr. 
Lock should apparently not be aware that there 
are several instances in which this has been done. 
We do not see where the ‘‘ logical difficulty ”’ lies; 
on the question of fact we regret to differ from Mr. 
Bateson, if his opinion is here correctly stated. 
The underlying idea in all that Mr. Lock has to 
say on the subject of adaptation by selection is the 
doctrine that specific differences arise by way of 
““mutation,’? or de novo, and not by the accumula- 
tion of continuous or “ fluctuating ’’ variations. The 
position is ably argued, and the results of the 
laborious experiments of de Vries and of the remark- 
abie work of Johannsen are brought to bear with the 
skilful touch of a genuine investigator who is per- 
sonally conversant with the matter in hand; nor does 
Mr. Lock’s general attribute of fairness here desert 
him. A point, however, on which we should like 
to be satisfied is this: the author asserts that ‘‘no 
one questions the validity of natural selection as a 
means of exterminating types which are unfitted for 
their environment’’; further, he thinks it at least 
probable that certain types have survived in conse- 
NO. 1955, VOL. 75 | 
quence of their “‘ fitness.’? But, since these latter 
types arose, as he would say, suddenly or discontinu- 
ously, how did it happen that they sprang into being 
in such exact harmony with their surroundings? 
Would Mr. Lock have us fall back upon the theory 
of ‘‘ directed variation,’’ or, what comes to the same 
thing, Paley’s view of ‘‘contrivance’’ by special 
creation? If it be replied that a well-adapted type 
must have arisen, not by one or more large muta- 
tions, but by a series of mutations both numerous 
and minute, we should wish to know how such 
mutations are to be distinguished from continuous. 
variations. To say, with de Vries, that selection 
of individual differences is powerless to raise per- 
manently the mean of a species, seems perilously like 
begging the question. As soon as the mean had’ 
been permanently raised, the result would be claimed 
as a mutation. 
We have space only for one further remark. If 
Mr. Lock will take his Aristotle again, and read, 
with its context, the passage he has quoted on p. 116, 
we think he will see that he has mistaken that philo- 
sopher’s meaning, as, indeed, Darwin did before 
him. BS AND: 
NOTES ON WATER PLANTS. 
Biologische und morphologische Untersuchungen 
tiber Wasser- und Sumpfgewdchse. 
Prof. Hugo Glick. Pp. xvii+256. 
Fischer, 1906.) Price 18 marks. 
Parte ii By; 
(Jena: Gustav 
HIS work forms the second instalment of the 
author’s studies on water plants. It deals 
chiefly with the European species and varieties of 
Utricularia, and, as was perhaps inevitable, one result 
has been to increase the number of the forms 
hitherto recognised as distinct. A prominent feature 
of the book lies in the attention devoted to the so- 
called Turions, or propagation buds, which occur so 
frequently in aquatic phanerogams. 
Several other aquatic genera also are dealt with, 
e.g. Ceratophyllum, in which Prof. Glick finds a 
specialised form of shoot provided with anchoring 
leaves, much reduced in character, which serve to. 
fix the plant in the mud. These leaves differ from 
the ordinary foliage leaves in the absence of chloro- 
phyll and in the almost complete suppression of the 
intercellular spaces so characteristic of the latter. 
The conclusions reached as to the morphological 
interpretation to be placed on the different parts of 
the Utricularia plants do not essentially differ from 
those drawn by Goebel about sixteen years ago as the 
result of an extensive series of investigations on 
tropical as well as on European species of this re- 
markable genus. The special feature of interest 
attaching to them lies in the impossibility of establish- 
ing a consistent distinction between the stem and leaf 
in these plants. One can pass into or be replaced 
by the other in the most irregular manner, and 
either of them may in turn be represented in position 
by one of the bladders that form so characteristic 
a feature of the genus. As Prof. Gliick remarks, the 
