134 



SCIENCE 



[N. S. Vol. LII. No. 1336 



waters. The Echinodennata, described by 

 Grieg, include 2 crinids, 6 starfish, 6 ophi- 

 ttrids, strangely only 1 sea urchin, and 4 holo- 

 thurians. The rest of the described marine 

 fauna consists of 2 sponges, 4 actinians, 6 

 sea-squirts, 10 hydrids, 4 medusse, and 44 

 kinds of polyehsete worms. Clearly Arctic 

 waters do not teem with a variety of animal 

 life, but they make up for this in abundance 

 of individuals. 



The geologic results of Per Schei are very 

 rich, not only in the abundance and variety of 

 fossils gathered, but also in the record of the 

 distribution of the various formations. Over 

 the Archeozoic granites of Ellesmere Land lie 

 about 14,000 feet of Paleozoic strata, begin- 

 ning with Upper Cambrian, followed by basal 

 Ordovician (Beekmantown), middle Ordovic- 

 ian, early and middle Silurian, and an extra- 

 ordinary development of Devonian, having a 

 thickness of about 6,000 feet (marine Lower 

 and early Middle Devonian and an Upper 

 Devonian fresh- water facies). The Carboni- 

 ferous is known only in highest Pennsylvanian 

 rocks, followed by marine Upper Triassic. 

 Then there is no sedimentary record of any 

 kind until the deposition of the Miocene 

 fresh-water beds with lignites. As Per Schei 

 died soon after the retiu-n of the expedition, 

 the fossils are described by O. Holtedahl in 

 three papers, one of which gives a summary 

 of the geological results attained. The land 

 plants of the Upper Devonian and the very 

 few from the Miocene are described by A. G. 

 Nathorst ; the Devonian fishes by J. Kiser ; the 

 Devonian invertebrates by O. E. Meyer and 

 S. Loewe; the Upper Carboniferous fauna by 

 T. Tschernyschew and P. Stepanow; and the 

 Triassic marine invertebrates by E. Kittl. 



From Per Schei's account and the splendid 

 photographs (the best Arctic pictures any- 

 where), it is evident that Ellesmere Land is 

 an elevated and dissected table land, rising 

 directly toward Greenland. Elevated strand- 

 lines and wave-cut terraces are seen along 

 most shores, and are of various altitudes up 

 to 5Y0 feet. On one at 300 feet lie imdecom- 

 posed driftwood and logs, attesting the recent- 

 ness of some of this elevation. 



Norsemen are still lovers of heroic work, 

 and the north lands are their special scientific 

 field. From them we are learning the geog- 

 raphy, geology, and biology of the lands of 

 the midnight sun on either side of Greenland, 

 the territory of the Danes. We need, how- 

 ever, still more information about these almost 

 inaccessible places, and let us hope that the 

 Norwegians will soon extend their endeavors 

 and modernize our knowledge of Nova Zembla. 



Charles Schuchert 



SPECIAL ARTICLES 



COMPUTING AGES OF ANIMALS 



In the various experiments on animals in 

 regard to growth, nutrition, activity, repro- 

 duction, etc., it is necessary to determine the 

 age of the individuals at various times in 

 their lives. These computations, involving 

 mere additions and subtractions, take a great 

 deal of the experimenter's time. The task is 

 monotonous and soon becomes a matter of 

 great drudgery. 



Having before me the task of making 

 several thousand such computations 1 sought 

 a means of obtaining this data in a quicker 

 and less tedious manner. The instrument 

 described and used by Minot in his work on 

 the guinea pig appealed to me. It had, how- 

 ever, the objectionable feature that the age of 

 but one animal could be ascertained at a time. 

 As I was dealing with a pair of animals 

 whose weights were made on the same day 

 and whose ages were to be determined when 

 litters were bom it was necessary to devise a 

 scheme whereby the ages of two individuals 

 born on different days could be readily deter- 

 mined at various times in their lives. 



The device iinally hit upon is so simple to 

 make and operate that I have deemed it 

 worthy of a description in order that others 

 who may be wrestling with such tedious com- 

 putations may be relieved of their drudgery. 



The device consists of three meter sticks, 

 M, A, and F, with two guides, 0, O. The 

 middle meter stick and the two guides are 

 fastened securely to a board and the other 

 two meter sticks slide freely. To facilitate 



