January 31, 1908] 



SCIENCE 



195 



ception of the unpaired chromosome, which 

 passes to one pole of the spindle. 



E. E. Gates 

 UmvEBSiTY OF Chicago 



CURRENT NOTES ON METEOROLOGY 

 AND CLIMATOLOGY 



changes op climate? 



In his recent volume (Vol. II.) on " An- 

 cient Khotan," Dr. M. A. Stein, whose ex- 

 plorations in Chinese Turkestan are well 

 known, points out that it requires constant 

 and persistent effort to keep up the irrigation 

 of the oases in that region. The wind-blown 

 sand and the shifting courses of the silt-laden, 

 snow-fed rivers are always tending to change 

 the course and scope of the irrigation systems. 

 If man relaxes his efforts in the least, the 

 sand and the aridity of the desert replace the 

 fertility of the formerly irrigated oasis. This 

 has happened in many cases within human 

 experience. A swing of the climatic pen- 

 dulum in this region, towards a drier period, 

 is not thought improbable, but the ordinary 

 physiographic forces at work there are held 

 sufficient to explain the changes of population 

 and of settlements which have been clearly 

 made out. 



Again, in the Lake Chad district of Africa, 

 Lieutenant Seeker, in northern Nigeria, has 

 lately reported that he found that the natives, 

 by erecting fish-dams on the river To, are 

 diverting water which would otherwise flow 

 into the lake. These dams collect large masses 

 of weeds, and lead to the formation of marsh- 

 land. Lieutenant Seeker is of the opinion 

 that this may have something to do with the 

 reported drying-up of Lake Chad. 



FOG DENSITIES 



The Quarterly Journal of the Royal Me- 

 teorological Society for October, 190Y, con- 

 tains a suggestion by J. A. Lovibond, " On a 

 Method and Apparatus for Measuring Fog 

 Densities." The method is based on the power 

 of selective absorption of suitably colored 

 glass. When this has been graded into me- 

 chanical scales of equivalent color value, a 

 beam of white light can be progressively ab- 



sorbed to extinction, and the luminous value 

 of each successive absorption stated in quanti- 

 tative terms. This analytical power also ap- 

 plies to the color constituents of the beam. 



rain gauges 

 The Quarterly Journal of the Royal Meteor- 

 ological Society for October, 1907, also con- 

 tains a paper, by Dr. H. E. Mill, on "The 

 Best Form of Eain Gauge, with Notes on 

 Other Forms." Dr. Mill strongly recommends 

 the " Snowdon pattern," which is 5 inches in 

 diameter; has a vertical rim to the funnel of 

 4 inches, and has an inner can and also a 

 bottle. 



NOTE 



The Annuaire Meteorologique of the Eoyal 

 Observatory of Belgium for 1907 contains a 

 discussion, by A. Lancaster, entitled " L'Hu- 

 midite de I'Air en Belgique," and an account 

 of balloon ascents in Belgium by J. Vincent. 

 E. DeC. Ward 



Harvard University 



THE IOWA LABORATORIES OF ANIMAL 

 BIOLOGY 



At the University of Iowa, new laboratories 

 of animal biology have just been put into 

 service under the directorship of Professor 

 Gilbert L. Houser. These laboratories are 

 located in a new and beautiful fire-proof bviild- 

 ing of thoroughly modern construction — the 

 hall of natural science, erected by the state at 

 an expense of three hundred thousand dollars. 

 With the standard of their new quarters, the 

 laboratories are entirely in keeping, so it is 

 evident that the opening of these laboratories 

 marks an epoch in the scientific facilities of 

 Iowa. 



The space devoted to animal biology com- 

 prises eleven rooms located in the north wing 

 of the building on the second, the first, and 

 the basement floors. This space is so unified, 

 however, by a small elevator running through 

 the rooms as to make the arrangement much 

 more convenient than if all the space were on 

 one floor. 



The laboratories proper occupy the whole of 

 the second floor of the north wing, the large 



