-™- 
——— 
FEBRUARY 12, 1914] 
agree with this conclusion. “It is quite possible,” 
he writes, “that Belt’s frog was Atelopus varius, 
Stannius, but it is more probable that it was 
Dendrobates typographus, Keferstein (ignitus, 
Cope), which occurs also in Nicaragua. All the 
Dendrobates appear to be very poisonous.” 
The section on mimicry of ants—one of the 
most important in the work—is enriched by an 
excellent summary, on pp. 114-23, of Wasmann’s 
splendid researches. 
Vosseler’s account of the life-history of the 
Locustid Eucorypha fallax is given at consider- 
able length and illustrated, on pp. 107-12. An 
ant-like larval stage of this insect was described 
long ago as Myrmecophana fallax by Brunner von 
Wattenwyl, and it is most satisfactory that Vos- 
seier’s excellent observations have now put this 
often-quoted example of mimicry in its true posi- 
tion. He shows that “after the fourth change of 
skin” there is “‘a change from a mimetic to a 
cryptic appearance,” the succeeding stage being 
leaf-like in colour and exhibiting a correspondingly 
altered behaviour. The change thus begun con- 
tinues to the end, the winged imago being beauti- 
fully leaf-like. In correspondence with these 
changes Vosseler does not admit that any feature 
in the likeness is unnecessary. And yet this was 
one of the very cases on which Brunner founded 
his conception of “hypertelic” resemblance, or 
resemblance that attains an altogether unnecessary 
perfection in detail—that is, in fact, “too good 
to be true.” 
The illustrations, especially those that are 
coloured, are rather rough, but they are, on the 
whole, well selected and serve their purpose. It 
is a pity that the two species of Heliconius figured 
on pp. 144 and 145 were not accompanied by 
Melinaea imitata and Mel. ethra, instead of 
Mechanitis doryssus and Mech. lysimnia respec- 
tively. If room could be found for only one 
Ithomaeine, there is no doubt that Melinaea 
should have been the genus selected. The mimetic 
females of the African Papilio dardanus are so 
complicated that much care is required to avoid 
mistakes. It is unfortunate that the only charac- 
teristic eastern and south-eastern Danaine model, 
Amauris echeria, and mimetic form (cenea) of 
dardanus should be described on p. 163 as West 
African. 
But when every criticism has been urged, we 
must admit that the book will be very useful. 
Haase’s important monograph is too large and ex- 
pensive to be likely to reach many hands, and we 
welcome the appearance of a German work of 
small price and moderate size, which will serve 
as an introduction to this interesting and much- 
debated subject. Deeley leo 
NO. 23II, VOL. 92] 
NATURE 
655 
ee 
TEXT-BOOKS OF CHEMISTRY. 
(1) General Chemistry Laboratory Manual. By 
Prof. J. C. Blake. Pp. x+166. (New York: 
The Macmillan Company; London: Macmillan 
and Co., Ltd., 1913.) Price 8s. net. 
(2) Practical Chemistry. Qualitative Exercises 
and Analytical Tables for Students. By the late 
Prof. J. Campbell Brown. Sixth edition. 
Edited by Dr. G. D. Bengough. Pp. 78. 
(London: J. and A. Churchill, 1913.) Price 
2s. 6d. net. 
(3) Organic Chemistry for Students of Medicine. 
By Prof. J. Walker, F.R.S. Pp. xi+ 328. 
(London: Gurney and Jackson; Edinburgh : 
Oliver and Boyd, 1913.) Price 6s. net. 
(4) Quantitative Analysis in Practice. By Prof. 
J. Waddell. Pp. vii+162. (London: J. and A. 
Churchill, 1913.) Price 4s. 6d. net. 
(5) La Catalyse en Chimie Organique. By Paul 
Sabatier. Pp. xiv+255. (Paris and Liége: 
Librairie Polytechnique, Ch. Beranger, 1913.) 
’ Price 12.50 francs. 
(1) HE exercises in this manual are com- 
plementary to the author’s “General 
Chemistry : Theoretical and Applied,” and accord- 
ingly the work can scarcely be recommended to 
chemical students in general unless they are taking 
a course very similar to that planned by the author. 
About one-half of the book, which is interleaved 
throughout with blank pages for students’ notes, 
is devoted to simple experiments, partly qualita- 
tive and partly quantitative, dealing with the 
chemistry of non-metallic  (“acid-forming ”) 
elements. The experiments on the metals (‘‘base- 
forming elements”) might serve as an introduction 
to inorganic qualitative analysis, but would be 
of slight educational value unless accompanied 
by a course of lectures on the theory of analysis. 
A few simple experiments on the atmosphere, the 
soil, fuels, and oils, natural waters, the ferrous 
metals, and rocks are grouped under the heading 
of applied chemistry. 
(2) This treatise, like the foregoing manual, is 
chiefly of interest as affording an indication of the 
subject-matter chosen for experimental study in 
the author’s practical classes. These exercises 
are preceded by the following general instruction : 
“After performing each of the following exercises, 
the student should record the reactions in his note- 
book in the form of equations whenever an equa- 
tion is possible.” This excellent instruction, if 
conscientiously obeyed by the student and care- 
fully supervised by a sympathetic demonstrator, 
would go far towards making the work educa- 
tional. Yet without previous knowledge gained 
either from text-books of general chemistry or 
from lectures on the theory. of analysis, the student 
