oo 
OcTOBER 2, 1913] 
difficult to carry out under the conditions of educa- 
tion in this country, our teachers could neverthe- 
less, provided they are sufficiently well conversant 
with the German language, gather a large amount 
of useful hints, even if only from the method 
of treatment of the material. For use in Germany 
we have no doubt that the teachers will hail 
gladly the appearance of this volume, and the 
distinguished list of co-workers with Prof. Héfler 
is sufficient indication to stamp the volume as 
one of a high order. 
Einfiihrung in die Agrikulturmykologie. By Prof. 
Dr. A. Kossowicz. 1. Teil: Bodenbakterio- 
logie. Pp. vii+143. (Berlin: Gebriider Born- 
traeger, 1912.) Price 4 marks. 
Pror. Kossowicz is to be congratulated on 
having condensed into such a small book a review 
of the chief publications on soil mycology. The 
book partakes, in fact, more of the nature of an 
introduction to the literature of the subject than 
to the subject itself. The mere enumeration of 
the various workers for and against a hypothesis, 
without any criticism from the author, is not 
calculated to afford much help to a beginner. The 
subject-matter is divided into sections dealing 
with the part played by bacteria in the cycle of 
the elements carbon, oxygen, hydrogen, nitro- 
gen, sulphur, phosphorus, and iron; the mycology 
of soil; the mycology of manure; and the influ- 
ence of the manurial treatment on the micro-flora 
of the soil. For such a small book the biblio- 
graphy is very comprehensive, constituting, as it 
does, about one-fourth of the total number of 
pages. The book is well illustrated, and as a 
short work of reference ought to prove of value 
to agricultural chemists and mycologists. 
LETTERS TO THE EDITOR. 
[The Editor does not hold himself responsible for 
opinions expressed by his correspondents. Neither 
can he undertake to return, or to correspond with 
the writers of, rejected manuscripts intended for 
this or any other part of Nature. No notice is 
taken of anonymous communications.] 
The Piltdown Skull. 
Ir had been my intention not to add anything 
further in print to my preliminary note (Quart. Journ. 
Geol. Soc., vol. Ixix., 1913, p. 145) on the cranial cast 
obtained by Dr. Smith Woodward from his recon- 
struction of the Piltdown skull until I was in a posi- 
tion to make a full and comprehensive statement as 
to the precise significance of the information afforded 
by the cranial fragments as to the kind of brain 
possessed by the earliest known human inhabitant of 
Britain. But, although my investigations are now 
sufficiently advanced to permit me to undertake the 
writing of my report, it will be some months before 
it can be published; and in the meantime it is most 
undesirable that the present widespread misunder- 
standings should be allowed to breed further trouble 
and confusion for those who are interested in the 
elucidation of Mr. Charles Dawson’s momentous dis- 
coveries. 
Recent events have made it difficult for those who 
have relied wholly upon what has appeared in print 
to form any accurate conception of the meaning and 
importance of the Piltdown skull-fragments. It is 
quite certain that they afford the first evidence we 
NO. 2292, VOL. 92] 
NATURE 131 
0 
have obtained of a hitherto unknown group of the 
Hominid, so fundamentally distinct from all the 
early fossil men found in Europe as to be worthy of 
generic distinction—a ‘‘dawn-man" of a very primi- 
tive and generalised type. Certain features are so 
clearly ape-like as definitely to confirm the generally 
admitted kinship to the African anthropoid apes, as 
well as to distinguish Eoanthropus sharply and clearly 
from all other human remains. In other respects, 
however, there is a closer resemblance to the features 
of modern man than is found in the specialised group 
of Neanderthaloid palzolithic men. This curious 
association of features is not paradoxical, as some 
people pretend. /The small and archaic brain and 
thick skull are undoubtedly human in character, but 
the mandible, in spite of the human molars it bears, 
is more simian than human. So far from being an 
impossible combination of characters, this association 
of human brain and simian features is precisely what 
I anticipated in my address to the British Association 
at Dundee (Nature, September 26, 1912, p. 125), 
some months before I knew of the existence of the 
Piltdown skull, when I argued that in the evolution 
of man the development of the brain must have led the 
way. ‘The growth in intelligence and in the powers 
of discrimination no doubt led to a definite cultivation 
of the zesthetic sense, which, operating through sexual 
selection, brought about a gradual refinement of the 
features.’’/ Just as the young child still uses its teeth 
for purposes of attack, so in the dawn of human 
existence teeth suitable for offensive purposes were 
retained long after the brain had attained its dis- 
tinctively human status and had made the hands 
even more serviceable instruments for attack. 
That the ape-like conformation of the chin region 
signifies the inability to speak is surely a patent 
fallacy. Articulate speech must have come while the 
jaws were still simian in character; and the bony 
changes that produced a chin were the result mainly 
of that process of refinement to which I have already 
referred, to the reduction of the teeth, which was 
part of the same process, and, quite in a minor degree, 
to that process of growth and specialisation of the 
genio-glossi muscles which resulted from their use in 
speech. : : ; 
A great source of misunderstanding will be got rid 
of if these obvious facts and the considerations based 
upon them be admitted. ‘ 
In conélusion, I may answer many questioners by 
affirming that I still hold to every word of my pre- 
liminary note published in the Quarterly Journal of 
the Geological Society, as well as of the statements 
made in my lectures delivered before the Royal Dublin 
Society and the Manchester Literary and Philosophical 
Society last winter, and also to the facts demonstrated 
in my exhibit at the Royal Society’s soiree in May. 
G. Ex.iot SMITH. 
University of Manchester, September 23. 
Solar Electrical Phenomena. 
In a lecture last January to the Christiania Academy, 
Prof. Birkeland? gave an interesting summary of his 
recent researches on solar and planetary electrical 
phenomena. He describes how in a study intended 
to elucidate the evolution of celestial bodies he 
examined the nature of the electric discharge taking 
place in vacuo in a large discharge vessel from a 
magnetisable globe serving as kathode. The experi- 
ments, which were made under widely differing condi- 
tions, were on a scale more ambitious than anything 
hitherto attempted. Two vessels of 300 and 1000 
litres’ capacity respectively were employed. In the 
larger of these the globe used was of 36 cm. diameter, 
1 “De Yorigine des mondes,” par K. Birkeland, Arch. Sci. phys. et nat. 
Genéve. Quatrieme Periode, t. xxxv., Juin, 1913. 
