156 



SCIENCE 



[N. S. Vol. LII. No. 1337 



a statistical standpoint the weather associated 

 with different types. 



Colonel Gold mentions the work of Captain 

 Brunt during the war, showing the relation 

 between the amount of low clouds in Flanders 

 at different hours and the general direction of 

 the wind. It appears that with the westerly 

 type there was decreasing cloudiness. 



The scheme of indexing, tagging and class- 

 ifying pressure charts is of course, not new. 

 Odenbach, Brandenburg and others have 

 made classifications for limited areas in the 

 United States, and Bowie and Weightman for 

 the whole country, giving with much detail 

 the storm paths. 



Some of the notes made on the different 

 types are extremely interesting: Thus, type 

 I. is very favorable for west winds at night; 

 and a notable instance occurred during the 

 battle of Cambrai, ISTovember 20, 1917; the 

 transitional type of fair weather in the even- 

 ing and inland fog in the morning, occurred 

 on March 20, 1918, when the Germans began 

 their great offensive. Evidently the German 

 forecasters picked the hour. And again May 

 27 to 31, 1918. Type III. is one that worries 

 the forecaster, for squalls come when he ex- 

 pects fair weather. He forecasts rain in 

 front of the trough and gets fair weather in 

 front and rain behind. On August 26, 1916, 

 seven British airplanes failed to return be- 

 cause of a squall coming from the west while 

 the planes were over the German lines. A 

 different type occurred in June, 1917, during 

 the battle of Messines, for which a week's 

 fair weather was accurately forecast. Type 

 ■IX. means unpleasant weather. "The most 

 noticeable example in history of this type," 

 says Gold, " is the one which persisted for the 

 first three days of August, 1917, during the 

 battle of Ypres." Type VI. is the typical 

 fair weather anticyclonic type. This type 

 prevailed at the time of the German offensive 

 in March, 1918, and also immediately after 

 the armistice. 



It is evident that the forecaster from now 

 on takes his place in all military coimcils for 

 both offensive and defensive operations. 



A. M. 



SPECIAL ARTICLES 



LINKED GENES IN RABBITS 



The so-called " English " rabbit possesses a 

 dominant pattern of white spotting. A homo- 

 zygous English mated with non-English rab- 

 bits produces heterozygous English young ex- 

 clusively. These mated with non-English rab- 

 bits produce equal numbers of English and 

 non-English young. Facts such as these show 

 conclusively that the English pattern is de- 

 pendent upon the inheritance of a single 

 Mendelian gene. I have recently discovered 

 that the gene in question is linked with an- 

 other gene, that for intense vs. dilute pig- 

 mentation. Dilution is a recessive character 

 alternative with intense pigmentation. In- 

 tense pigmentation is seen in rabbits of the 

 varieties, gray, black and yellow. Dilute pig- 

 mentation is seen in blue-gray, blue, and 

 dilute yellow rabbits. 



In a certain experiment, I crossed a black 

 English rabbit with a blue non-English rab- 

 bit. A male from this mating was black 

 English in appearance, but from his parent- 

 age was known to be heterozygous both for 

 English and for intensity. He was subse- 

 quently mated with blue non-English females, 

 which of course would be homozygous for the 

 recessive member of each of the two character 

 pairs. If no linkage occurred between the 

 two pairs of characters, young would be ex- 

 pected of four classes all equally numerous, 

 viz., (1) English intense, (2) Non-English 

 dilute, (3) English dilute, and (4) Non-Eng- 

 lish intense. Classes (1) and (2) would rep- 

 resent the original, non-crossover groups, 

 classes (3) and (4) would represent novel, 

 crossover groups. In a series of matings ex- 



