May 11, 1883.] 



SCIENCE. 



385 



cellules above the external auditor}' meatus ; 

 and rarety a third branch is directed more 

 anteriorly. 



While the atrium of the tj-mpanum varies 

 but little in size, the attic and mastoid antrum 

 vary greatlj'. 



The mastoid cellules ' consist of air-cavities 

 of variable number, size, and extent, in the 

 midst of the sfiongj' substance of the mas- 

 toidea. They are commonly more or less pro- 

 portioned in number and size with age. With 

 the advance of j-ears, they increase in both 

 respects from the conversion of the ordinarj' 

 marrow-filled, spongj' substance into vacant 

 spaces. Later they increase in capacity b}' 

 expansion and coalescence, and proportion- 

 ately decrease in number ; and often in old age 

 some of them even exceed in size the antrum. 

 The cellules communicate with one another, 

 and, through the sides and extremitj', with the 

 mastoid antrum. 



Some small but important foramina and 

 canals of the temporal bone, besides those 

 mentioned, are worthy' of notice. 



In the ridge separating the jugular fossa 

 from the entrance of the carotid canal, there is 

 a fine canal which ascends to the tj'mpanum. 

 It communicates with the atrium at the inner 

 part of the floor, beneath the promontorj', and 

 is thence continuous with a groove ascending 

 and dividing into several branches upon the 

 latter. The canal gives passage to the tj-m- 

 panic nerve, which is distributed- upon the ' 

 promontor}-. 



Among the nutritious foramina of the carotid 

 canal, chiefij' on its oiiter wall, there are 

 several larger ones, which communicate with 

 the tympanum, and transmit one or two minute 

 arteries and connecting branches of the tym- 

 panic nerve with the sj'mpathetic nerve. 



Likewise, in the jugular fossa, there are 

 several foramina communicating with the tym- 

 panum for the passage of minute veins. An- 

 other foramen in the fossa extends in a fine 

 canal outwardl}', and opens into the fissure 

 between the mastoid and auditory processes. 

 The canal transmits the auricular branch of 

 the vagus nerve, and, in its course, communi- 

 cates with the facial canal. 



On the inner extremity' of the tegmen, a 

 cleft or groove ends in a fine canal, which 

 proceeds outwardly' to the inner side of the 

 receptacle of the tympanic tensor, and com- 

 municates with the tympanum. The canal 

 transmits the small superficial petrosal nerve. 

 Another small groove on the tegmen, close to 

 that for the large superficial petrosal nerve, 



^ Mastoid sinuses. 



likewise ends in a fine canal, communicating 

 with the facial canal, for the transmission of 

 the least superficial petrosal nerve. 



THE WEATHER IN MARCH, 188S. 



The floods reported last month have nearly 

 subsided, though their evil eifects will con- 

 tinue to be felt for mam- months. The Mis- 

 sissippi remained above the danger-line at 

 Cairo till the 12th ; at Memphis, till the loth. 

 It was two feet above danger-line at Vicks- 

 burg, and ten inches below the same at New 

 Orleans, on the 31st. The heaviest losses 

 were on the west bank in Arkansas, and here 

 they were more serious than in 1882. It is 

 stated, that on the 11th, to the south of 

 Helena for a distance of two hundred miles, 

 nearly the entire country for about thirtj' 

 miles from the river was flooded, and a great 

 number of cattle were lost. On the St. Fran- 

 cis River there was more devastation than in 

 1882 ; in the vicinity of Oldtown, near Hele- 

 na, the flood was the worst ever experienced. 

 The situation is more favorable at INIemphis 

 than last 3'ear. There will be no interference 

 in planting the crops between Cairo and Vicks- 

 burg. And while, in 1882, at least 20,000 

 destitute people were supported more than a 

 month by the goyernment, the losses this j'ear 

 are confined mostly to the drowning of stock. 

 The heavy rains of the 20th and 21st caused 

 damaging freshets in the maritime provinces 

 of Canada. 



The chart on p. 386 exhibits mean isobars, 

 isotherms, and wind-directions, for this month. 

 A comparison with the similar chart for Feb- 

 ruary, published in Science, April 13, shows 

 that the winter area of permanent high press- 

 ure, which in February was very extensive, 

 and nearly divided in two by the Rocky Moun- 

 tain range, had moved to the east of that 

 range, and was central in northern Montana. 

 This area, in connection with the prevailing 

 north-west winds, accounts for the low tempera- 

 tures of the east. These present a marked de- 

 ficiency in all sections east of the 97th meridian, 

 the mean being 3.2° below the normal. The 

 lowest temperature reported was — 34°, on 

 Mount Washington, the 5th. 



Eleven storms have been traced whose 

 tracks lay either in the United States or a 

 little to the north of the boundary. The fol- 

 lowing table exhibits the number and mean 

 velocity' of storms in each March since 1877, 

 so far as they were sufficiently marked to en- 

 able a velocitj- to be determined. 



