102 



APPENDIX. 



remained half an hbur in the bowl it came out, and was found to have absorbed nearly 

 half its own weight iu water. 



The geographical distribution of ti'ee frogs over the globe gives to America the majo- 

 rity of species known to exist, for of 64 species described, no less than 37 are found on 

 our continent, — and, of the remainder, one is found in Southern Europe ; five are pecu- 

 liar :o Africa ; eight to Asia, and ten to Australia and the Indian Archipelago. 



The Hylodidaj, of which our Pickerings Hylodes is a member, are peculiar to the Ame- 

 rican continent and West Indian islands, and of this family eight species are known to 

 science. I may remark that the Hylodes differs from the Jlyla in having the fingers free 

 while the hitter has them more or less webbed generally, though not always. The toes 

 in the Hylodes are free, while in the Hyla they are, with the exception of one species, 

 broadly webbed. In the Hylodes also the disks are small, while in the Hyla •^^hey are 

 i^ery consf>icuous. 



J. M. Jones. 



CRUDE NOTES ON STORMS, AND HOW TO NOTE THEM. 

 Br -J. L. HuRDis, Cor. Member of the Institute. 



If the eqiiator be coBsidered a region of heat and moisture, and the poles of the 

 earth regions of atmospheric condensation, precipitation, and frost, the 90° which sepa- 

 rate these parts of the «arth must necessarily be subject to various conditions of tempera- 

 ture, arising not only from change of seasons, but, in particu ar, fro mthe the direction 

 of the wind; for, as all winds from equatorial regions are warm winds, rarified by heat, 

 and charged w'ith evaporation, so all winds proceeding from either of the poles, will be 

 ■cold winds, comparatively devoid of heat and moisture. Consequently, a Barometer, 

 placed in any intermediate latitude, will rise when the condensed and heavier atmosphere 

 -of the polar regions approaches i', and vice versa, fall, when in contact wi h rhe rarified, 

 moist, and lighter atmosphere from the regions of the equator. 



Thus do the extremes of heat and cold govern the atmospheric circulation of the 

 globe — the superabundant heat and moisture of the equator flowing towards the poles, 

 and the dry, condensed atmosphere of the frozen regions overflowing towards the 

 -equator. 



If we examine the lettering of the Barometer prepared under the instructions of the 

 late Admiral Fitzroy for the use of our sea-going populati m, and which we may presume 

 to represent his personal experience on this point, so far as the northern hemisphere is 

 concerned, we find al! the indications for a rise to be northerly, or what may be termed 

 polar, — while on the opposite side the indications of a fill are entirely of a southern or 

 tropical character, and accord precisely with the principles I have now endeavored to 

 lay down. The lettering below this, extending to the bottom of the scale, is exceptional, 

 purely cyclonic in character, and therefore not applicable to the ordinary currents of at- 

 mosphere which prevail in every quarter of the globe. 



We are still imperfectly acquainted with the nature of the cyclone or revolving 

 stc(rm. That these storms are generateil by heat, within certain parallel* of latitude, 

 extendmg around the entire globe, appears to be well authenticated. In the northern 

 Lemisphere this region may be said to extend from the 10th to the 20th degrees Of lati- 

 tsde, iind is sejiarated from a similar zone in the southern hemisphere by the great equa- 

 torial belt of calms" and constant rain. 



