NOTES AND LITERATURE. 155 
proceeds to give a neat and convincing account of what is meant by 
a “descriptive” science and points out how a number of modern 
critics have misinterpreted the term. In their desire to show that 
all science is only descriptive they have failed to discriminate 
between orderly sequences, such as night following day, and neces- 
sary sequences, such as the explanation of the alternation of night 
and day as the outcome of the revolution of the earth on its 
axis, etc. 
After discussing whether the simplest organisms — bacteria for 
instance — might be accounted for as the outcome of a physico-chem- 
ical accident, Biitschli asks: If this is possible, can the same assump- 
tion account for the highly complicated organism? This leads toa 
discussion of what is meant by “chance” or “accident.” Bütschli 
points out that one of the chief peculiarities of living things is their 
power of reproducing other living things like themselves, so that if a 
given form once arose by chance, its continuation does not any longer 
depend on chance, since by its own nature it reproduces that special 
group of **accidents " that brought it into existence. The argument 
leads naturally enough to Darwin's hypothesis of the origin and sur- 
vival of chance variations. Bütschli affirms his belief that up to 
the present no better hypothesis has been advanced to explain the 
adaptation of organisms to their environment. There follows an 
admirably clear analysis of what we mean by adaptation. It would 
lead too far to enter into this discussion, but we cannot refrain from 
expressing great admiration for the clearness and ability with which 
the subject is handled. : 
Pflüger's “teleological causal law" is skillfully divested of its meta- 
physical covering. Bütschli points out that the same law is equally 
applicable to a steam engine with a regulator. Cossmann's recent 
argument, in which he attempts to demonstrate a special “ biological " 
sequence of causes and effects in organisms as contrasted with the 
sequence in the inorganic world, is severely criticised and its fallacy 
exposed. T 
Bütschli points out that Driesch's demonstration of vitalism rests 
on a very doubtful assumption.. If it could be shown, as Driesch 
claims, that the reorganization of a piece of an egg or of an adult 
into a new whole with proportionate parts isa phenomenon peculiar 
to living things, then Bütschli admits that Driesch might make good 
his position, but that this is true is by no means proven to be the 
case. Asa parallel inorganic phenomenon it is pointed out that » 
drop divided in two forms two new drops. Again, if a drop of some 
