Tiddeman.
(17) ‘Ossemens Fossiles.’  Cuvier.
(18) ‘Reliquiae Diluvianae.’  Buckland.
(19) “Fossil Mammalia”—­’Zoology of the Voyage of the Beagle.’ 
     Owen.
(20) ’Description of the Tooth and Part of the Skeleton of the
     Glyptodon.’  Owen.
(21) “Memoir on the Extinct Sloth Tribe of North
     America”—­’Smithsonian Contributions to Knowledge.’  Leidy.
(22) “Report on Extinct Mammals of Australia”—­’British Association,’
     1844.  Owen.
(23) ’Description of the Skeleton of an Extinct Gigantic Sloth
     (Mylodon robtutus).’  Owen.
(24) “Affinities and Probable Habits of Thylacoleo”—­’Quart.  Journ. 
     Geol.  Soc.,’ vol. xxiv.  Flower.
(25) ‘Prodromus of the Palaeontology of Victoria.’  M’Coy. (26) ‘Les Ossemens Fossiles des Cavernes de Liege.’  Schmerling. (27) ‘Die Fauna der Pfahlbauten in der Schweiz.’  Ruetimeyer. (28) “Extinct and Existing Bovine Animals of Scandinavia”—­’Annals
     of Natural History,’ ser. 2, vol. iv., 1849.  Nilsson.
(29) ‘Man’s Place in Nature.’  Huxley.
(30) ‘Les Temps Antehistoriques en Belgique.’  Dupont. (31) “Classification of the Pleistocene Strata of Britain and the
     Continent”—­’Quart.  Journ.  Geol.  Soc.,’ vol. xxviii.  Boyd Dawkins.
(32) ‘Distribution of the Post-Glacial Mammalia’ (Ibid.), vol. xxv. 
     Boyd Dawkins.
(33) ‘On British Fossil Oxen’ (Ibid.), vols. xxii. and xxiii.  Boyd
     Dawkins.
(34) ‘British Prehistoric Mammals’ (Congress of Prehistoric
     Archaeology, 1868).  Boyd Dawkins.
(35) ‘Reliquiae Aquitanicae.’  Lartet and Christy.
(36) ‘Zoologie et Paleontologie Francaises.’  Gervais. (37) ‘Notes on the Post-Pliocene Geology of Canada.’  Dawson. (38) “On the Connection between the existing Fauna and Flora of
     Great Britain and certain Geological Changes”—­’Mem.  Geol. 
     Survey.’  Edward Forbes.
(39) ‘Cavern-Researches.’  M’Enery.  Edited by Vivian.
(40) “Quaternary Gravels”—­’Quart.  Journ.  Geol.  Soc.,’ vol. xxv. 
     Tylor.

CHAPTER XXIII.

THE SUCCESSION OF LIFE UPON THE GLOBE.

In conclusion, it may not be out of place if we attempt to summarise, in the briefest possible manner, some of the principal results which may be deduced as to the succession of life upon the earth from the facts which have in the preceding portion of this work been passed in review.  That there was a time when the earth was void of life is universally admitted, though it may be that the geological record gives us no direct evidence of this.  That the globe of to-day is peopled with innumerable forms of life whose term of existence has been, for the most part, but as it were of yesterday, is likewise an assertion beyond dispute.  Can we in any way connect the present with the remote past, and can we indicate even imperfectly the conditions and laws under which the existing order