Oct. 23, 1873] 
NATURE 527 
supra-marginal convolution as arching over the end of 
the fissure of Sylvius and joining the upper temporo- 
sphenoidal convolution, and the angular as folding over 
the hinder end of the parallel fissure and joining the middle 
temporo-sphenoidal convolution. This description, and 
it is supported by our experience, is not quite in accord- 
ance with that of some other anatomists; for in- 
stance, in Mr. Marshall’s well-known essay on the brain 
of the bushwoman, the supra-marginal convolution is 
correctly defined thus, whilst the angular would require 
the anterior enlarged portion of the third annectent 
gyrus, as marked in the figure, to complete its bend and 
unite it to the second temporal gyrus. Similarly, in the 
_ idiot boy’s brain, the angular gyrus would be a large 
folded convolution, there indicated as the bifurcated 
anterior extremity of the second annectent convolution ; 
and in the idiot woman the parallel fissure extends so far 
back that it quite cuts off the angular gyrus from the 
temporo-sphenoidal, and the convolution is represented 
by the straight, also bifurcated fore part of the second 
annectent gyrus in the figure. The intra-parietal fissure 
of Turner is here called less correctly inter-parietal. 
In the occipital lobe, a tolerably constant transverse 
depression, into which the intra-parietal fissure often 
debouches is appropriately named “occipital sulcus.” 
Prof. Ecker regards the bridging, or annectent convolu- 
tions, as unworthily distinguished by special names in 
the human brain, since they do not bridge over any fissure 
as in the lower apes. He carefully points out their 
homology with those gyri in the ape, yet deprecates the 
transference of the names from the Simian to the human 
brain. But this comparison and correspondence of no- 
menclature is precisely what we require for the satisfac- 
tory determination of the cerebral functions, and the 
homological significance of a part is quite sufficient to 
justify the application of the same name to it. So also, 
on the inner surface, the lower annectent gyrus is described 
as the “gyrus cunei,” and the occasional presence%of the 
upper annectent gyrus is alluded to, of which we have now 
seen several examples. The operculum of the ape’s brain 
is discussed, but the same term is unfortunately here 
applied to quite a different part of the human brain, viz. 
the united lower ends of the ascending frontal and pari- 
etal convolutions which overhang the island of Reil. 
The middle convolution on the under surface of the 
occipito-temporal lobes is regarded, not without precedent, 
as the direct continuation of the gyrus fornicatus, and the 
uncinate gyrus of Huxley thus comes to be divided into 
three parts, the “lingual lobule” behind the union of the 
two gyri, the “convolution of the Hippocampus” imme- 
diately below the dentate fissure, and the recurved hook 
or “uncinate lobule”; but the connection between the 
gyrus fornicatus and this convolution is small and nar- 
row, whilst that between it and the lingual lobule is large 
and direct ; further, the author points out, after Gratiolet, 
that in many apes the calcarine is prolonged into the 
dentate fissure and cuts off the arched from the uncinate 
gyrus; surely this shows the essential unity of the 
uncinate convolution, and that the junction with the 
gyrus fornicatus is a superadded and secondary element 
in the human and certain Simian brains. 
The translator has generally performed his work well ; 
there are, however, one or two slips; for instance, the 
dentate fissure is said to produce an eminence in the floor 
of the Zosterior corner of the lateral ventricle; the 
parieto-occipital fissure also is described correctly as 
being concave forwards, whilst in the diagram it is repre- 
sented as convex: the figures are exceedingly clear. 
Prefixed is an exhaustive bibliography by the translator, 
which adds materially to the value of the work; and 
finally, we can cordially recommend it as an accurate 
and lucid guide to a somewhat difficult study. 
Gi. Deis 
OUR BOOK SHELF 
The Zoological Record for 1871. Edited by Prof. Newton. 
(J. Van Voorst, 1873.) 
THE birth of true biological science is of so recent origin, 
and its development has been so rapid that until lately 
many of the necessary steps in the furtherance of its 
proper progress have remained beyond the cognizance of 
its most enthusiastic followers. The difficulties connected 
with, and the unmanageableness of the large number of facts 
accumulated day by day on all branches of zoology, and 
recorded by observers in all parts of the civilised world, 
have until lately been scarcely realised. Only by those 
who, from the disappointment which they have experi- 
enced on finding that observations which have cost them 
incalculable time and labour, have been previously under- 
taken and exhausted by others before them, either in 
their own or some other country, appreciate fully the 
necessity for an easily accessible, accurate, and not over 
ponderous account of the labours of previous workers. 
It is only the full appreciation of the advantage to 
future science students which stimulates the authors of 
the several parts of the work before us to continue and 
commence their contributions to this, what may be truly 
termed, labour of love. The labour involved in obtaining 
a complete and condensed account of the gist of each 
zoological paper published here or elsewhere throughout 
a year, is so great, and the smallness of the class who are 
disposed to purchase the work when produced, so neces- 
sarily restricted, that at first sight it is evident that it is 
only with the assistance of donations from scientific 
bodies, or from contributions of one kind or another on 
the part of amateurs in the subject, that the necessary 
expenses can be covered and the staff maintained. 
These considerations will recommend this valuable 
work to the consideration of all interested in zoological 
progress. 
LETTERS TO THE EDITOR 
[The Editor does not hold himself responsible for opinions expressea 
by his correspondents. No notice is taken of anonymous 
communications. | 
On the Equilibrium of Temperature of a Gaseous 
Column subjected to Gravity 
Srnce reading Principal Guthrie’s first letter on this subject 
(vol. viii. p. 67), I have thought of several ways of inves- 
tigating the equilibrium of temperature ina gas acted on by 
gravity. One of these is to investigate the condition of the 
column as to density when the temperature is constant, and to 
show that when this is fulfilled the column also fulfils the con- 
dition that there shall be no upward or downward transmission 
of energy ; or, in fact, of any other function of the masses and 
velocities of the molecules. But a far more direct and general 
method was suggested to me by the investigation of Dr. Ludwig 
Boltzmann* on the final distribution of energy in a finite system 
of elastic bodies. A sketch of this method as applied to the 
simpler case of a number of molecules so great that it may be 
treated as infinite, will be found on p. 535. Principal Guthrie’s 
second letter (vol. viii. p. 486) is especially valuable as 
stating his case in the form of distinct propositions, every cne or 
* Studien iiber das gleichgewicht der lebendigen Kraft zwischen bewegten 
materiellen Punkten. Von Dr. Ludwig Boltzmann. Sitzb. d. Akad. d. 
Wissensch, October 8, 1868 (Vienna). 
