396 
NATURE 
[JUNE 20, 1912 
rationals (or irrationals) f/(x)=0o, whereas, if the 
field of « is the continuum, f/(x) does not exist. 
The remaining chapters are rather of the nature 
of recreations; at least, they deal with less con- 
troversial matters. The one on algebraic equa- 
tions is very good; that on the theory of numbers 
is rather old-fashioned, but a good introduction 
to standard treatises; there is one on the problem 
of the regular polygons; and finally a very in- 
teresting one on the transcendence of e and 7. 
The proofs given here are remarkably simple, con- 
sidering the difficulty of the problem, and ought 
alone to give the book a wide circulation. 
In conclusion, emphasis should be laid on the 
fact that none of the writers propose, and many 
of them expressly deprecate, any attempt to make 
school teaching of mathematics strictly logical in 
the present sense of the term. Teachers, we hope, 
will bear this carefully in mind. It will do them 
infinite good to appreciate these new discoveries, 
and it will do their pupils good to have some of 
them stated, without any attempt at proof. The 
main improvement, however, to be immediately 
expected is that the teacher should more fre- 
quently say, “I am going to assume” so-and-so, 
instead of either tacitly assuming it or else 
dogmatically treating it as a necessary truth. 
Gaba 
IMPRESSIONS OF A GUIANA FOREST. 
Under the Roof of the Jungle: a Book of Animal 
Life in the Guiana Wilds. By Charles L. Bull. 
Pp. xiv-+271+60 plates. (London: Duckworth 
and Co., r911.) Price 6s. net. 
HE author, having come across a copy of 
Waterton’s “Wanderings in British 
Guiana,’ was so much impressed with it that he 
“went to Demerara, well equipped with sketch- 
books and colour-hox, and wandered through the 
jungle, the splendid, colourful, weird, living 
jungle.” Having sailed up the great rivers to 
make detailed studies of the landscape and to 
watch the timid wild creatures come stealthily 
forth from their hiding-places, he tells us that 
he climbed up among the tangle of lianas into the 
very roof of the jungle until he could look out 
and watch the sun set over it, and watch the 
birds and beasts of the day disappear whilst the 
night-wanderers came forth. We are not told 
how long and how often he stopped there, but he 
cannot have wasted his opportunities, else, with 
more luck than is enjoyed by other ardent 
naturalists in a tropical forest, he could not have 
watched so many scenes from start to finish 
which he describes in his pleasantly written 
chapters. 
NO. 2225, VOL. 89] 
The burden of the book is that “life in the 
jungle is a tragedy; everywhere the killers lurk 
or roam”; and dominant in the solemn chorus to 
the multitudinous tragedies is the tolling note of 
the bell-bird, which is described as the ‘sexton 
of the jungle.” 
Without exception the many creatures are well 
characterised and described without any scientific 
pretences. Monkeys, capybaras, anteaters, 
harpies, king vultures, savannah birds, ana- 
condas, and crocodiles, they all disclose their 
most intimate feelings, although in all fairness 
be it stated that these are not talking-animal 
stories. “The red brigade,” namely, the scarlet 
ibis, is a touchingly-told tale of the doings of that 
pest, the plume-hunter. 
Naturally the big cats take a great part in the 
book. A jaguar plays with a coiled-up armadillo 
as a kitten plays with a ball, slays a peccary, and 
then travels for half a mile over the jungle-roof, 
catches a spider-monkey which with many others 
flashed past him, frightened by a boa in an orchid- 
clad tree. A fight between the cat and this snake 
ends with the death of the reptile, but after many 
further adventures retaliation comes through the 
deadly bite of a bushmaster snake. Another 
jaguar attacked a tapir, which shook off the 
enemy by taking to the river, but whilst still in 
midstream the tapir was soon finished by the 
dreaded Carib fishes. 
The book is embellished with numerous illustra- 
tions, sixty full-page plates “from drawings from 
life by the author,” who obviously belongs to the 
impressionist school, and some of these drawings 
seem at first sight ludicrously overdone. But 
they are not. The creatures themselves are repre- 
sented in the most lifelike attitudes, all very 
characteristic and correct to detail; whilst the 
vegetation, the immediate environment, produce 
exactly that bewildering impression which one 
receives whilst attention is fixed upon the main 
thing, the creature crouching or moving in a 
gloomy light. 
AND SOUL. 
Body and Mind: a History and a Defence of 
Animism. By Wm. McDougall. Pp. xix+ 
384. (London: Methuen and Co., Ltd., 1911.) 
Price ros. 6d. net. 
HIS is a thoroughly exhaustive treatise pre- 
ale senting to the reader the arguments which 
through the ages have been advanced for and 
against the existence of “the soul,” and the most 
captious critic could not accuse the author, while 
revealing himself as an animist, of being unfair 
to the opponents of animism. 
BODY 
