September 23, 1887.] 



SCIENCE. 



151 



contain an invertebrate fauna identical with that of the Laramie 

 group. 



With regard to vertebrate remains, this objection does not apply; 

 and, could they be made to harmonize with themselves, they might, 

 perhaps, be trusted to some extent as indices of synchronism in 

 widely separated localities. But, as shown by Cope, they do not 

 thus agree, for the Laramie forms include genera that are re- 

 garded as characteristic of Cretaceous, and others that are regarded 

 as characteristic of Tertiary strata. This should surprise no one- 

 The law that has been laid down by paleontologists, that the same 

 epochs in geologic time produced the same living forms, is contrary 

 to the now well-established principles of geographical distribution, 

 according to which the earth is subdivided into a large number of 

 faunal areas more or less clearly marked off one from another. 



The peculiarity of this principle, which is of most importance to 

 paleontology, is that these territorial subdivisions represent faunas 

 not merely different from one another, but showing different de- 

 grees of biologic development as development is supposed to have 

 gone on in the animal kingdom. Eveiy one knows that the fauna 

 of Australia belongs to an undeveloped type, being marsupial in 

 aspect so far as its mammals are concerned. The types of South 

 America are lower than those of North America, and the latter 

 lower than those of Asia and Europe. If all the present faunas of 

 the g'lobe were buried under its soil, it is clear that it would not only 

 be impossible to harmonize the deposits of different continents, but 

 that the inference now freely drawn by paleontologists, that the 

 less developed forms demonstrate their existence at earlier epochs, 

 would lead to grave mistakes and be generally false. New Zealand 

 is now in its age of birds, while the Galapagos Islands are still in 

 that of reptiles, or the mesozoic age. 



The difficulties in the way of geological synchronism arising 

 from the geographical distribution of organisms are not lessened 

 when we pass from the vertebrate fauna to the flora of the Lara- 

 mie g'roup ; for, taking the present flora of the globe as a crite- 

 rion, we find that the geographical distribution of plants is more un- 

 even than that of animals. Floral realms are more numerous and 

 distinct than faunal realms ; and the more serious obstacle, that 

 some areas furnish types representing less developed floras than 

 others, exists here, as in the case of animals. The proteaceous and 

 myrtaceous flora of Australia may be regarded as rudely corre- 

 sponding to its marsupial fauna. Hence, although the vegetable 

 fossils of the Laramie group are especially remarkable for their 

 great abundance and variety, Mr. Ward concedes that the age of 

 the Laramie group cannot be proved by its flora alone. 



The more particular comparison and discussion of the Upper 

 Cretaceous or Senonian, Laramie, and Eocene floras is introduced 

 by a table covering 72 pages, and giving the geographical and 

 stratigraphical distribution of every authentic species from these 

 formations. The discussion concludes with the statemei-, luat the 

 Laramie flora as closely resembles the Senonian flora as it does 

 either the Eocene or the Miocene flora. But this does not neces- 

 sarily prove either the Cretaceous age of the Laramie group or its 

 simultaneous deposit with any of the Upper Cretaceous beds. The 

 laws of variation and geographical distribution forbid us to make 

 any such sweeping deductions. With regard to the first point, it is 

 wholly immaterial whether we call the Laramie Cretaceous or 

 Tertiary, so long as we correctly understand its relations to the 

 beds below and above it. We know that the strata immediately 

 beneath are recognized Upper Cretaceous, and we equally know 

 that the strata above are recognized Lov\'er Tertiary. Whether this 

 great intermediate deposit be known as Cretaceous or Tertiary is 

 therefore merely a question of a name, and its decision one way or 

 another cannot advance our knowledge in the least. 



The synopsis concludes with notes on the various localities where 

 the Laramie plants were collected, and 35 double plates, with 139 

 figures. 



Types of the Laj-amie Flora. (U.S. Geol. Surv., Bull. No. 37.) 

 By Lester F. Ward. Washington, Government. 8°. 

 This rather bulky bulletin is supplementary to the preceding 

 synopsis. The 139 figures are reproduced on 57 octavo plates, 

 and are accompanied by critical comments, and descriptions of the 

 new genera and species. 



NOTES AND NEWS. 

 On Tuesday the 20th, in the presence of the secretary of the 

 navy, the naval committee of the House of Representatives, and 

 many representatives of the army and navy of this and other 

 countries, an exhibition was given in New York Bay of the destiTic- 

 tive capabilities of the Zalinski pneumatic dynamite gun. The 

 results of the tests made at the time prove conclusively, that, with 

 the pi'^sent experimental and necessarily imperfect gun, a shell con- 

 taining fifty-five pounds of explosive gelatine may be thrown with 

 accuracy a distance of one mile, and exploded at the proper 

 moment for producing the maximum of destructive effect. The 

 target used was the two-masted schooner 'Stillman,' eighty tons' 

 burden, late of the United States Coast Survey, but recently con- 

 demned, and reserved to be used in torpedo experimenting. She 

 was anchored 1,980 yards from Fort Lafayette, where the gun was 

 stationed. After two trial-shots with blank cartridges, a loaded 

 shell was fired, which struck the water a few yards short of the 

 target. The explosion threw a column of water nearly a hundred 

 feet into the air, and the concussion jarred the vessel so that the 

 mainmast was broken off a few feet above the deck. The next shot 

 struck the vessel at or below the water-line, with an instantaneously 

 destructive result. The schooner was lifted up, fairly torn apart 

 amidships, and the rails were under water in less than thirty 

 seconds, only the foremast and its standing rigging being left in 

 view. All around this floated small fragments of the schooner. In 

 each of these instances the gelatine was exploded by percussion in 

 this way : a small electric battery was affixed to the side, the only 

 thing lacking to start its operation being moisture. A thin piece 

 of blotting-paper kept this out. When the shell was immersed, 

 the moisture admitted generated sufficient electricity to fire a de- 

 tonator of fulminate of mercury, which exploded the gelatine. 



— R. Nahrwoldt has made a series of experiments on the gradual 

 loss of electricity of electrified bodies (A'rt/'z^rw. Rundschau, ii. No. 35). 

 In an essay published in 1878 the author proved that the discharge 

 takes place by means of the particles of dust suspended in the air. 

 These are electrified and then repelled from the electrifying body. 

 The result of these experiments led Lodge and Von Obermayer to 

 their method of clearing rooms from smoke. Later on, it was shown 

 that a wire of platina made red-hot by electricity electrified the sur- 

 rounding air, although it was almost free of dust. For this reason 

 Nahrwoldt resumed his experiments. He found that electricity was 

 discharged through a point only in dusty air. He made his experi- 

 ments in an air-tight glass shade the sides of which were covered 

 with a thin layer of glycerine. After the dust was precipitated on 

 the sides of the glass through the action of the electricity, the dis- 

 charge was very slight. As soon as a wire of platina was electri- 

 fied, and became red-hot, electricity was again discharged through 

 the point. Nahrwoldt concluded that this was due to particles fly- 

 ing from the red-hot wire. This conclusion was proved to be cor- 

 rect by the occurrence of platina in the deposits on the sides, and by 

 the loss of weight of the wire. These experiments led him to the 

 conclusion that air free of dust cannot be electrified statically. 



— We learn that the pecuniary loss attending the publication of 

 the Zoologischer Jahresberichi has been so great as to make it 

 necessary henceforth to restrict the scope of the work. Systematics 

 and faunistics are to be excluded. HYie. Jahresberichi is published 

 under the able editorial supervision of Dr. Paul Mayer of the Naples 

 Zoological Station, and has now reached its eighth year. Four 

 heavy volumes have hitherto been issued each year, giving accurate 

 and comprehensive summaries of all the zoological work done dur- 

 ing the year under review. The Jahresberichi is one of the most 

 difficult, most expensive, and at the same time most valuable, 

 zoological serials ever undertaken. About thirty reporters (Refer- 

 enten), distributed among different countries, have been employed 

 in collecting, summarizing, and arranging this vast work. The task 

 has been faithfully and most thoroughly accomplished, and we 

 most earnestly hope that the number of subscribers may be at once 

 increased to an extent that will insure its continuance on the same 

 broad plan that has hitherto been followed. The Jahresberichi 

 has become our vade-mecum ; and we can but regard it as a seri- 

 ous misfortune to have its scope narrowed. Are earnest zoologists 

 in this country willing to see such a work as this interrupted for 



