320 

change are retained when, by grafts or cuttings, the plants are 
removed to other localities. I have here, however, and ex- 
hibit with this paper, evidence of bud variation, in which 
there is no possibility of hybridism,—a root of the common 
sweet potato, Convolvulus batatas, in which some of the tubers 
are of the red Bermuda, and the others of the white Brazilian 
variety. ‘The sweet potato never flowers in this part of the 
country, so that seminal power could have had no influence 
whatever on the phenomenon. Even in the south, and I believe 
elsewhere, where this plant is cultivated for its roots, it rarely 
flowers, and I think there is little doubt but that the whole ten 
or twelve varieties under culture have originated without seed, 
and in the way we see them here. The points I wish to make in 
this paper are :—1st. That identical varieties sometimes appear 
in localities unfavourable to the idea of a common centre of 
origin. 2nd. Varieties have originated in which probably no 
hybridism or any seminal agency operated. 3rd. Varieties have 
certainly originated in the sweet potato by evolution, with- 
out seminal agency, and that the same variety in this way 
has appeared in widely-separated districts. 4th. As the dis- 
coveries of Darwin have shown, in many cases, varieties to be 
the parents of species, species may originate in widely-separated 
localities by bud variation.—‘‘ A Sketch of the Classification 
of the American Anserinz,” by B. H. Bannister. The follow- 
ing remarks are based upon an examination of the specimens of 
American geese in the collection of the Smithsonian Institution. 
The subfamily Anserinze by many recent authors is made to in- 
clude the genera Dendrocygna and Chenalopex, and doubtlessly 
correctly. In the present paper, however, we shall not consider 
these genera, leaving them provisionally out of the sub-family ; 
if included, they would form at least one well-marked section, 
following those we are about to describe. The distinguishing 
characters of the Anserinze, as thus limited to the true geese, 
are, the lengthened tarsus, covered with hexagonal or subquad- 
rate scales ; the neck more elongated than-in the ducks and less 
so than in the swans; the short, high bill gradually narrowing 
toward the tip, which is altogether composed of the large re- 
curved nail ; together with the more or less terrestrial habit 
of life, and the usually similar plumage of the two sexes. 
The geese of the North American continent have been long 
known, and being for the most part closely allied to, and in |, 
many cases identical with, well known European forms, they 
fall readily into the systematic subdivisions based upon the 
latter. Another basis of division of the American Anserinz is 
found in the presence, in two species—one North American and 
the other a Southern form—of deep rough superorbital depres- 
sions and reversed relative proportions of the tarsus and middle 
toe, together with an exclusively sea-coast habitat, and a carni- 
vorous diet, corresponding in some of these respects to the 
Oidemiz and Somateriz amongst the ducks. These latter 
characters we have taken as the basis of the two sections into 
which we divide the subfamily, as at present considered, since 
they correspond with equivalent characters in one of the sub- 
divisions of the Fuligulinz. The presence of the deep super- 
orbital depressions is a very general character amongst the 
carnivorous Natatores, though not universal. 


BOOKS RECEIVED 
EnGitsu.—The Year-Book of Facts for 1871: J. Timbs (Lockwood and 
Co.).—A Treatise on the Action of Vis Inertia in the Ocean: W. L. Jordon 
(Longmans and Co.). 
ForeiGn.—(Through Williams and Norgate)—1°" Nachtrag zum Lehrbuche 
der Aufbereitskund: P. R. von Rittinger.—Biblioteca Malacologica, 11., 
Ipsa Cheireghinii Conchylia di Spiridion Brusina — Populire wissenchaftliche 
Vortrige: H. Helmholtz. 
PAMPHLETS RECEIVED 
ENGLISH —Quarterly Weather Report of the Meteorological Office, July- 
October 1869.—On the Relations between Chemical Change, Heat, and 
Force: the Rey. H. Highton.—On Ocean Currents: James Croll.—On 
the Cause of the Motion of Glaciers: James Croll.—Letter to the Right 
Hon Col. Wilson-Patten on the Future Establishment and Organisa- 
tion of our Land Forces: Lieut.-General Sir Percy Douglas, Bart.—Report 
of the Cheltenham College Natural History Society for the year 1870.— 
Statistical Keview of Ten Years of Disease in Manchester and Salford : 
Dr. A. Ransome.—Double Spectra: W. Marshall Watts.—On the Spectra 
of Carbon: W. Marshall Watts.—On the Reason why the Difference of 
Reading between a Thermometer exposed to Direct Sunshine and one Shaded 
Diminishes as we Ascend in the Atmosphere: James Croll.—An Address 
read at the Anniversary Meeting of the Pntomplsecal Society of London, 
January 23, 1871: Alfred R. Wallace-—On the Chemical Composition and 
Microscopic Constitution of certain Cornish Rocks: J. A. Phillips.—Pro- 
pee of the Somersetshire Archzological and Natural History Society for 
1868-69. 
AMERICAN AND CoLoniAL,—Report of the Present Condition of the Geo- 
jogical Survey of Victoria.—Reports of the Mining Surveyors and Registrars 
NATURE 



| Fed. 16, 1871 

(Victoria) for the Quarter ending September 39, 1870.—Abstracts of English 
and Colonial Patents and Specifications refating to the Preservation of Food, 
&c.: W. H. Archer (Melbourne).—Patents and Patentees ,Victoria), 1814- 
186% ; Index to ditto for 1868 and 1869; Abstracts of Specifications of Patents 
applied for from 1854 to 1866, Ac-Bu (Victoria): W. H. Archer —Descrip- 
tions of new Fossil Shells of the Upper Amazon: T A. Conrad (from the 
American Yournal of Conchology).—Report of Committee on New Keme- 
dies to the Muskingum County, Ohio, Medical Society for October, 1870 
(Buffalo). 
ForeiGN.—Die Geschichte der Forschungen iiber die Phosphorite des 
mittlern Russlands von W. v. Gutzeit (Riga).—Rendiconti del reale istituto 
lombardo, Ser. ii. vol. 3, fasc 19, 20, and vol. 4, fnsc. 1.—Correspondenzblatt 
der Naturforscher-vereins zu Riga. 


DIARY 
THURSDAY, Fesrvary 16. 
Roya Society, at 8.30—On some of the more important Physiological 
Changes induced in the Human Economy by Change of Climate, as fiom 
Temperate to [ropical, and the Reverse (concluded): Dr. Rattray, R.N. 
—On a Registering Spectroscope: Dr Huggins, F.R.S. i 
SocreTy OF ANTIQUARIES, at 8.30.—On the Topography of Jerusalem, with 
special reference to the results obtained by the Palestine Excavation Fund 
and the Site of the I'emple of Antonia and of the Acra: Thomas Lewin, 
M.A., F.S.A. 
Linnean Society, at 8.—On Tremellineous Fungi and their Analogues: L. 
R. and C. Tulasne.—Bryological Remarks: S. O, Lindberg, M. 
CHEMICAL Society, at 8, 
Roya InsTiITUTION, at 3 —Davy’s Discoveries: Dr. Odling. 
FRIDAY, FEBRUARY 17. 
Rovat InsTITUTION, at 9.—On the Wolf-Rock Lighthouse: James N. 
Douglass. 
GEOLOGICAL Society, at 1.—Anniversary Meeting. 
Roya COLLEGE oF SURGEONS, at 4.—On the Teeth of Mammalia: Prof. 
Flower. 
SATURDAY, Fesrvary 18. 
Royat Institution, at 3.—Socrates: Prof. Jowett. 
SUNDAY, FEsRuARY 109. 
Sunpay Lecture Soctety, at 3.30.—On the Religion of Health: Dr. 
Elizabeth Blackwell. 
MONDAY, Fesruary 20. 
ENTOMOLOGICAL Sociery, at 7.—On the Dispersal of Non-m‘gratory Ins 
by Atmospheric Agencies: Mr. Miiller. 
Vicroria INsTITUTE, at 8.—Phyllotaxis; or the Arrangement of Leaves 
according to Mathematical Law: Prof Henslow. 
Roya CoLLeGe or SuRGEONS—On the Teeth of Mammalia; Prof. Flower. 
Lonpvon InstTiTuTION, at 4.—On the First Principles of Biology: Prot. 
Huxley. (Educational Course.) 
Roya Untrep Service InstTituTIoN, at 8.30.—On the Turret Ships now 
building for Her Majesty's Navy: E. J. Reed, C.B. 
TUESDAY, FEsrRuary 21. 
Zoo.ocicat Society, at 9.—Note on the Zwxza from the Rhinoceros: 
Dr. W. Peters, F.M.Z.S.—Remarks on certain species of Abyssinian Birds: 
J. H. Gurney.—On certain Indian Reptiles; Dr. J. Anderson. 
Samer riees Society, at 7.45.—On Currency and Pauperism: Mr, Ernest 
eyd. 
Rone INSTITUTION, at 3.-—Nutrition of Animals: Dr, Foster. 
WEDNESDAY, FEBRUARY 22. 
SocieTy or Arts, at 8.—On Water Meters: F. E. Bodkin. 
GEOLOGICAL Society, at 8. 
Royat Cot_ece or SURGEONS—On the Teeth of Mammalia: Prof. Flower. 
Roya Unitep Service INSTITUTION, at 8.30.—The Organisation of our 
Military Forces: Lieut.-Colonel Arthur Leahy, R.E. (Adjourned Dis- 
cussion.) 
THURSDAY, Fesruary 23. 
Roya Society, at 8.30. 
Society or ANTIQUARIES, at 8.30. 
Roya. INnsTITUTION, at 3.—Davy's Discoveries : Dr. Odling. 
Lonpon INSTITUTION, at 7.30.—On the Action, Nature, and Detection of 
Poisons: F. S. Barff, M.A., F.C.S. 



CONTENTS 
Tue EpucaTion oF Civit ENGINEERS . . . 
PAcE 
eC Ome ch 
RECENT PETROGRAPHICAL LITERATURE. II. By Arcu. Getkige,F.R.S. Ces 
Gopman’s Natura History OF THE AZORES . . « . e « = + 303 
Our Book SHEEF s, <.« s .» [lus in| (6 |= is Los) soja suse ip En 
LETTERS TO THE EDITOR :— ‘ 
Scientific Instruction in Elementary Schools —H. ULLyYETT . . 305 
The Prevalence of West Winds.—). J. Murry, F.G.S.. . . . 306 
Can Weather be Influenced by Artificial Means?—J. K. LAUGHTON 306 
Natural Science at’‘Cambridge ©... ss = «| = = «| o) seam 
Glass Globes.—J. Gwyn JEFFREYS, F.R.S. . . . «Vs Seeger 
The Primary Colours—F. T. MotT. « . - 2 2 «© « « «© «© 307 
Yellow.—C. J. WoopwarD . . . » « =» = « «, Jun tere 
Meteor—Rev. J. M. Witson . . . s+ - es o 8 2 « « 308 
Snake Bites.—i._L."PATTERSON 2-2 3 Ss. on 6) ou soe 
The Cretaceous Period.—T. M‘K. HuGues, F.G.S. . . . . « 308 
Insulation of St. Michael's Mount, Cornwall.—R. EpMonps . . 309 
Aurora Borealis: (.) 20.6. 15) cfc, giteuian ke! ig ne a EE 
Tse THeory or Gtaciat Motion. By A. R. Wactacz, F.Z.S.. . 309 
AN AccoUNT OF THE ECLIPSE AS SEEN FROM VILLASMUNDA BY AN 
UnscienTIFIC OBSERVER. By H. SAMUELSON, M.P. (With [dlustra- 
i en ee cewek oe 
NOTES «5.0. 6) 4) ofouie oh Be font meee eens an cin 
Mount WASHINGTON IN WINTER . 2. « 2 © «@ - © «© 6 o © STH 
SCIENCE IN VICTORIA . o22_ 6 We Sees FS a gts 
Tue CONTRACTION OF THE Eartu, By Prof. B. Perrce. . <<! ars. 
SocIETIES AND ACADEMIES. 2 ee elm = © = 5 0,0 6 6 s03KO 
Books AND PAMPHI.ETS RECEIVED. « + + «© + «© © «© © © «© «© 320 
DIARY 2 6:0 ee ee swe) we ene (s,s; ale ie) cals ee eae 
