1899] THE NORTH AMERICAN SLIME-MOULDS 449 
have been recognised in the United States. One degenerate species, Plas- 
modiophora brassicae, occasions the disease known as “club-root” in cabbage, 
and ‘ finger-and-toe” in turnip; while it is alleged that Plasmodium malariae 
may be the cause of malarial fever, and if it turn out to be a slime-mould, then 
the group suddenly acquires an unusual human interest. Apart from these 
two the slime-moulds are of no economic importance. Advice is given regard- 
ing the collecting and preserving of material, but the greater part of the book 
is taken up with classification. The descriptions of the genera and species are 
most carefully given, while the measurements of the spores are in microns. 
For the sake of the British farmer we wish that the following statement 
made by Professor Macbride regarding Plasmodiophora were true for the 
British Isles :— 
“Careful search continued through several years has not availed to bring 
this species to my personal acquaintance.” It is unfortunately too true, 
however, that British farmers lose thousands of pounds annually through the 
ravages of Plasmodiophora in their turnip crops. 
A CRITICISM OF THE BIOLOGICAL GOSPEL. 
From Comte to Benjamin Kidd. The Appeal to Biology or Evolution for 
Human Guidance. By RopertT Mackintosu, M.A., B.D., D.D., 
Professor at Lancashire Independent College. xxii. +287 pp. Lon- 
don: Macmillan and Co., 1899. 
“The appeal to biology, outlined by Comte, newly defined and emphasised 
by Darwinism, has now been stated in the most extreme form logically possible,” 
by Mr. Benjamin Kidd. Dr. Mackintosh has weighed the results of this appeal 
in the balances and finds them very short weight. In fact, he indicates that the 
appeal is gratuitous. There is available elsewhere much better guidance for 
human conduct than biology can offer, and the appeal to biology is apt to be 
misleading, as well as unsatisfactory. These are hard words, but it must be 
remembered that biology is still very young, much too young to give advice. 
Some have tried to force its hand and the results do not look well, but it was 
not a fair game to play. The science is too young to become a basis for the art 
of life. 
The author is brilliantly clever ; there is not a dull page in the book, perhaps 
not a dull sentence ; his criticisms of even purely biological matters make one 
feel what the science has lost in his being outside of it. To contradict him is 
impossible, for he is so reasonable ; to correct him is impossible, for the time is 
not yet ripe; to believe him is (for a biologist) impossible, for he proves too 
much. It seems to us that biology, preoccupied with its own concrete problems, 
has simply stammered like a child when forced to confront the big problem of 
human life; it has something to say, but it is not ready to say it. That it 
will eventually have a rational word to say, and one which will rhyme with the 
best word of the moralist, we never doubt. 
Part I. deals with Comtism, the appeal to biology, the appeal to history, and 
the doctrine of altruism. Part II. discusses the “simple evolutionism” of 
Spencer and Leslie Stephen. Part III. deals with Darwinism, or Struggle for 
Existence, and includes a splendid chapter on the metaphysics of natural 
selection. Part IV. has to do with Weismann and Benjamin Kidd, so widely 
apart, and yet in one respect so near akin. Finally we have a summary and 
conclusions. It is easy to write these lines; but to criticise is another matter, 
and we frankly confess that we must refrain, though the temptation is great. 
We refrain for this reason, that although we are unable to agree with the author’s 
central conclusions, we feel that he has done great service in showing that the 
appeal to biology is premature. X. 
