JUNE 20, 1912] 
NATURE 307 
No fewer than 148 pages are devoted to pro- 
pounding the arguments against animism, how 
this view held the field in the most ancient times 
and among the most ignorant savages and was 
gradually beaten back by the advance of learning, 
especially during the last half-century when the 
functions of the brain and their relationship with 
mental processes were submitted to physiological 
research, 
The author then critically examines the various 
anti-animistic hypotheses, demonstrates wherein 
they are inadequate and shows, in a scholarly 
study of the various mental faculties, how paral- 
lelism, associationism and various mechanistic 
doctrines fail to explain the facts of mentation; 
and his conclusion is that, since none of these 
views is satisfactory, we are driven back time 
after time to the conception of “the soul.” 
We have learned a very great deal from careful 
perusal of Dr. McDougall’s book, but in the end 
are bound to say that we lay it down unconvinced. 
The knowledge of the anatomy and physiology of 
the nervous system has increased enormously of 
recent years, but every physiologist, psychologist 
and neurologist knows only too well that that 
knowledge is still a very long way from complete. 
To argue, therefore, from our ignorance that our 
inability to explain certain phenomena postulates 
the existence of a soul is to take up the position 
of the animists of fifty years ago, from which they 
have been driven over and over again by the 
advance of science. 
Moreover, Dr. McDougall’s arguments, based 
on profound knowledge and careful thought as 
they undoubtedly are, are all negative. We had 
hoped to find a positive argument in his chapter 
on “the bearing of the results of ‘psychical re- 
search’ on the psycho-physical problem,” but all 
that the author himself can claim for this evidence 
is that 
“one of the advantages of the animistic solution of | 
the psycho-physical problem is that its accept- 
ance keeps our minds open for the impartial con- 
sideration of evidence of this sort, . . . whereas 
parallelism (including under that term all forms of 
the anti-animistic hypotheses) closes our minds 
to this possibility.” 
The book is worth reading for the historical 
part alone, inasmuch as it condenses into a most 
readable form a full account of the various psycho- 
physical doctrines for the past 3000 years; and 
the fascinating manner in which the author pre- 
sents the animistic position of the present day is | 
sure to earn for the volume a place on the book- 
shelf of every psychologist, be he professional or 
amateur. 
NO. 2225, voL. 89| 
OUR BOOKSHELF. 
Der Malvenrost (Puccinia malvacearum, Mont.): 
Seine Verbreitung, Natur und Entwickelungs- 
geschichte. By Jakob Eriksson. Kungl. Svensk. 
Vetenskap. Handl., 47, No. 2. Pp. 125+ Taf. 
1-6. (Upsala and Stockholm: Almgqvist and 
Wiksells; London: W. Wesley and Son, 1911.) 
Dr. Eriksson has given an exhaustive account of 
his researches, extending over many years, of the 
distribution, nature, and life-history of the well- 
known Hollyhock rust. The point of greatest 
interest generally is that dealing with the spread 
of the fungus and its continuance in time, which 
turns, as those conversant with the author’s views 
would expect, on the presence of myceplasm in 
the cells of the host. This conception is generally 
scouted in England, owing to experiments con- 
| ducted along wrong lines, and accepted as a refu- 
| tation. Hollyhock seeds containing mycoplasm are 
very abundant; if such are sown the resulting 
plants at the age of about three months are badly 
attacked by rust, the outcome cf mycoplasm 
present in the seed, which passed along with the 
growing plant. This is termed the primary erup- 
tion, and is independent of outside infection. The 
spread of the disease now subsides for a time, and 
| the host plant continues its growth. 
Eventually a second wave of disease attacks the 
plant, due in this instance to the dispersion of the 
spores produced during the primary eruption. 
From this time onwards the disease is spread by 
the liberation of spores. The spores produced by 
the first and second eruptions, although morpho- 
logically indistinguishable, are biologically quite 
| distinct. 
In the second wave of infection spores 
of two kinds are produced; in other words, the 
spores germinate in two different ways. Some 
spores on germination produce the well-known 
stout promycelium, which gives origin to second- 
ary spores. Other spores on germination give 
origin to a long, thin, straight filament, the tip of 
which gives off minute conidia. When leaves are 
infected by means of the secondary spores, the 
disease appears after an interval of from ten to 
twenty days, whereas when leaves are infected 
with conidia, no disease in the form of spore 
pustules results, but the leaf-cells become charged 
with mycoplasm. 
The various phases from infection by means of 
conidia to mycoplasm in the seed or permanent 
parts of the host-plant, and the gradual conversion 
of the mycoplasm into tangible mycelium, produc- 
ing the first wave of disease, are fully described, 
and figured on six beautifully illustrated plates. 
| Life and Health, with Chapters on First Aid and 
Home Nursing. (Health Reader III.) By Dr. 
C. E. Shelly and E. Stenhouse. Pp. viii + 237- 
(London : Macmillan and Co., Ltd., 1911.) Price 
Is. 8d. 
Or the many books due to the demand for teaching 
in hygiene and temperance in public elementary 
schools, this is one of the best. It is designed to 
meet the suggestions in the Education Code of 
1909, and is specially adapted to children of twelve 
