108 NATORE 
[APRIL 4, 1912 
genera, but nothing of a very novel or remarkable 
nature. A few new genera which are established 
for species of Peridinium scarcely seem to be 
sufficiently characterised, and may perhaps be 
accepted as subgenera. 
New forms are added in every group of the 
Microplankton, but perhaps the most notable 
additions to knowledge are in “Groupe V— 
Organismes énigmatiques,” where a large number 
of curiously shaped things are described and 
figured as being related to Halosphera, Ptero- 
sperma, and their allies, but some of which one 
cannot help thinking may eventually prove not to 
be Protista at all, but the eggs and egg-coverings 
of some of the Metazoa. 
The Tintinnide and allied Infusoria are very 
fully treated, and then a few Rhizopoda bring the 
first part of this report to an end; and the second 
part—nearly half of the volume—is found to be 
devoted wholly to Diatomacea. It is almost with 
a feeling of relief that one finds that not many 
new forms are added to this already enormous 
group, and that most of the space is devoted to a 
discussion of the occurrence and condition of 
known species, many of them common forms in our 
own British seas. In a final note to the Micro- 
plankton we are promised a supplement in tabular 
form dealing in detail with the distribution and 
abundance of the more common species when the 
remainder of the plankton has been reported on. 
We look forward with interest to the publication 
of the remaining volumes. 
Altogether this is a notable series, upon the 
appearance of which the leader of the expedition, 
his collaborateurs, and the authors of the reports 
may alike be congratulated. 
W. A. HERDMAN. 
Untersuchungen iiber Linkshandigkeit und die 
funktionellen Differenzen der Hirnhdlften nebst 
einem Anhang: Ueber Linkshdndigkeit in der 
deutschen Armee. By Dr. Ewald Stier. Pp. 
iv+352+59. (Jena: Gustav Fischer, r1grt1.) 
Price ro marks. 
NE of the most striking features that serve 
to distinguish man from all other creatures 
is his ability to learn to execute skilled movements 
of a much greater variety, complexity, and preci- 
sion than are attainable by the rest of his order. 
But an even more interesting human trait is re- 
vealed in the fact that in the vast majority of 
mankind the right hand and the apparatus which 
controls its movements are more apt to acquire 
this skill and to develop its innate potentialities to 
a much higher degree than the left hand is 
capable of. 
NO. 2214, VOL. 89] 
That in a small minority of people this state of 
affairs is reversed, and the left hand becomes 
more highly endowed with the inborn aptitude to 
learn and readiness to perform the more complex 
and finely adjusted movements, has ever provided 
food for reflection. For the condition of left- 
handedness interests not only the student of bio- 
logy, but also those who concern themselves with 
educational policy, the devotees of sport, and the 
“man in the street’’?; and quite a considerable 
literature has grown up from the repeated discus- 
sions in which this interest has materialised, 
culminating in this characteristically Teutonic 
treatise or encyclopedia of all that bears upon the 
left-handed person, his anatomy, his mental and 
moral qualities and weaknesses. 
It has been assumed as an axiom by almost 
everyone who has discussed these problems 
hitherto that the greater skill of the right hand, 
in the majority of mankind, necessarily implies 
‘a superiority of the left cerebral hemisphere, 
which controls the movements of the right hand— 
a superiority not only in the mere regulation of 
skilled motion, which is obvious, but also in its 
psychical potentialities, which has always seemed 
to me to be a gratuitous and wholly unjustifiable 
assumption. 
The result of this confusion of ideas has been 
that most investigators have endeavoured to find 
some anatomical peculiarity in the left cerebral 
hemisphere, or some favourable circumstances in 
the arrangements for its nutrition which would 
explain this imaginary predominance. But most 
of such researches have led to a result which their 
authors regard as utterly enigmatic—that if there 
is any evidence of superiority of one cerebral hemi- 
sphere over the other it is more often the right, 
and not the left, that excels. 
The most instructive illustration of this line of 
argument is the late Prof. Cunningham’s Huxley 
memorial lecture, delivered in 1902, for he de- 
veloped it in his usual lucid manner, and frankly 
admitted that he had reached conclusions pre- 
cisely the reverse of what he had expected. 
But though he confessed that he had _ been 
baffled, his belief in the existence of the functional 
superiority of the left cerebrum was not lessened. 
In the British Medical Journal of August 29, 
1908, I protested against the whole assumption 
involved in this argument that the control of 
skilled movements of the right arm and the 
muscles of speech represent the sum total of the 
higher psychical manifestations of the human in- 
tellect. Dr. Stier does not seem to be aware of 
this criticism, for his treatise may be regarded as 
a great expansion and elaboration of the theme 
and the mode of treatment adopted by Prof. Cun- 
