2/' 



NA rURE 



[January i8, 1900 



materials. These Prof. Spencer intends to secure with 

 all possible speed, and to that end he is already lay- 

 ing plans for renewed exploration of the Bush and the 

 Interior. It is his intention to make the museum at 

 once a thoroughly representative Australian Collection 

 and a great Educational Institute. In this he has a 

 labour of years ; and that he will succeed we have not the 

 sliglitest doubt, for pluck, endurance, farsightedness and 

 enthusiasm are in him unusually combined. 



1 he work of the Sydney Museum has, rapidly deve- 

 loped in interest and importance during recent years ; 

 the introduction of " new blood " there, as more recently 

 at Adelaide and now at Melbourne, has brought to bear 

 upon the investigation of the indigenous fauna and the 

 natural resources of the country, now so largely dying 

 out, a body of earnest students intent on work while 

 yet it is not too late. The present memoir, which is 

 an outcome of this movement, may thus be regarded 

 as a sign of the times ; and we sincerely hope that those 

 which are to follow will be pushed forward with all 

 possible speed, it being now five years since the discovery 

 of the remains of which it treats was announced. 



FLOATING STONES. 



DURING my recent visit to South-West Patagonia, in 

 1899, for excavations in the remarkable Glosso- 

 therium or Neomylodon Cave near the farm Puerto 

 Consuelo or Eberhardt, I made, with my fellow traveller. 

 Dr. O. Borge, the following curious observation. Whilst 

 rowing in the long and narrow channel of Ultima 

 Esperansa, to study the plankton, we observed, when the 





fragments had a mean weight of o"3 gram. The 

 fragments contain no air cavities perceptible to the 

 unaided eye. They must, therefore, not be confounded 

 with the volcanic ejections (and perhaps slags from 

 meteors) with its numerous air cavities which are often 

 found drifting on the surface of the ocean. 



The following consideration will help to explain the 

 apparently paradoxical fact that stone fragments of a 

 specific gravity of 271 and a weight up to 08 gram have 

 been observed floating on a fluid of a specific gravity 

 of I 005. On examining the floating stones one could 

 discern small gaseous bubbles attached to the under 

 surface of theiri, and at the shore stones can be seen on 

 the very fringe of the beach which are just beginning to 

 float lightened by gaseous bubbles. Unfortunately, I had 

 not occasion to investigate the conditions more closely, 

 as I was busy with other researches ; neither had I any 

 apparatus at my disposal for the collection of the gas that 

 had accumulated under the stones. It is probable that 

 the stones were not only provided with gas bubbles, 

 which can be perceived by the eye, but that they were 

 surrounded by an envelope of gas supported by an in- 

 significant coating of algas, of which the stones are sur- 

 rounded. At least, traces of diatoms and algie are 

 discernible on the stones after drying. The greasy- 

 surface of the mineral of which the floating stones con- 

 sisted also prevented the water from adhering to them, 

 and caused the stones to be surrounded with a concave 

 meniscus, which naturally may have contributed to, and 

 perhaps was the main cause of, their floating, which some- 

 times was further facilitated by a patelliform shape of 

 some of the bigger stones. 



The observed phenomenon is not without some geo- 

 logical interest. In the described 

 manner a considerable transport of 

 solid matter takes place, not only 

 in the narrow Patagonial channel, 

 but no doubt also at several 'Other 

 shores of the ocean ; and new 

 strata will be built up possibly en- 

 closing mixture of remains from far 

 distant geological periods. 



Eri.and Nordenskiold. 



Fragments of slate found floating upon the sea-surface at S.W. Pat.agonia 



sea was calm or only agitated by a slight swell, small 

 fragments of slate which floated upon the surface packed 

 together in larger or smaller clusters. They drove 

 hither and thither in the neighbourhood of the shore, 

 until they were driven away by the strong current which 

 at intervals swept forward in the channel. The quantity 

 was considerable ; for instance, 700 of them were 

 obtained at one cast of the net in a few minutes. The 

 stones had evidently drifted out from the beach, which 

 consisted mainly of similar stone fragments washed off 

 from the cliff's composed of a bituminous mesozoic slate. 

 The surface of the stones Was dry, and they sank 

 immediately when it became wet by touching or by the 

 movement of the swell. 



The slate fragments collected on the sea-surface had a 

 specific gravity of 271. The specific gravity of the water 

 in the channel was only foo49 at a temperature of 15° C 

 (59^^ F). The largest stone which 1 obtained from the 

 surface (pictured in natural size on the accompanying 

 zincotype) weighed o'B gram. Twenty of the smaller 



NO. 1577, VOL. 61] 



DR. ELLIOTT COUES. 



BY the death, on Christmas Day, 

 of Dr. Elliott Coues, America 

 loses one of its leading ornitho- 

 logists ; indeed, we may say, with- 

 out disparagement of others, the most 

 prominent since Spencer ]5aird was 

 taken from us. Born in 1842, at 

 Portsmouth, in New Hampshire, and 

 graduating in the Columbian University, Coues entered 

 the medical service of the United States Army in 1862, 

 receiving the brevet rank of Captain for his conduct 

 during the war, after which he held several appointments 

 of various kinds, and especially one in Arizona, which 

 gave him the opportunity of indulging his inborn taste for 

 natural history. Subsequently he held in succession the 

 posts of Professor of Zoology in the University of Nor- 

 wich, in the State of Vermont, of Anatomy in the National 

 Medical College at Washington, and of Biology in the 

 Virginia Agricultural College, besides being, in the in- 

 terim, surgeon and naturalist to the United States 

 Northern Boundary Commission, and from 1876 to 1880 

 secretary and naturalist to the United States Geological 

 and Geographical Survey of the Territories. The duties 

 of these different offices seem only to have stimulated 

 his efforts, and the number of his zoological papers con- 

 tributed to various scientific journals would alone accord 

 him a high place ; but, apart from them, his " Birds of 

 the North- West," his " Fur- bearing Animals," and "Birds 



