862 



THE POPULAR SCIENCE MONTHLY. 



others, as the Charleston Mountains, push 

 their lofty summits into so cold an atmos- 

 phere that they obtain a covering of the bo- 

 real pines and firs. These higher mountains, 

 when rising from the lower Sonoran deserts, 

 present in succession all the extratropical 

 /ones of North America, which, from their 

 close juxtaposition, may be here studied to 

 unusual advantage. In ascending or de- 

 scending such slopes the change from one 

 zone to another is quickly recognized, and 

 the altitude of first appearance of the various 

 new species encountered may be recorded 

 with considerable confidence. Not so, how- 

 ever with the species lost, for, except in the 

 case of trees and such strikingly conspicuous 

 forms as the yuccas, some of the cactuses, the 

 creosote bush (Larrea), and a few others, it is 

 exceedingly difficult to detect the disappear- 

 ance of species when passing out of their 

 ranges. 



The Rattlesnake's Rattle. The idea that 

 the rattles of a rattlesnake correspond with 

 its years is, according to Dr. Arthur Strad- 

 ling, incorrect. "When the little Crotalus 

 is born," this author says, " its tail is fur- 

 nished with a single tip of horn, incapable of 

 producing any sound by the violent vibration 

 which its owner nevertheless communicates 

 to it when excited. In some near relations 

 of the rattlesnake, such as the purucncu of 

 Brazil, this horny claw or nail persists 

 throughout life without addition thereto. 

 But in the rattlesnakes proper and there 

 are many species of them two, and some- 

 times three, joints appear during the first 

 few months of the creature's life ; then and 

 later there is probably no definite relation 

 between their number or frequency of de- 

 velopment and its age, though they may be 

 proportionate in some measure to its rate of 

 growth. Broods of young serpents belong- 

 ing to this genus which I have reared have 

 exhibited great diversity in this matter ; so 

 much so, that it has been impossible to base 

 any calculation on obsei'vations of the phe- 

 nomena presented by them. The overlap- 

 ping 4 thimbles ' or cones of which the rattle 

 is composed are thin, dry, and exceedingly 

 brittle, and in consequence the instrument is 

 easily broken off when it has reached the 

 length of from one to two inches, though 

 longer specimens are occasionally seen; 



twenty joints make an exceptionally big 

 rattle. This shedding of the rattle is in all 

 cases accidental, and is due to external 

 causes, not a constitutional and periodical 

 function like the casting of the skin. When 

 it breaks off at the root or in the middle, 

 there is generally no trace left of a fracture 

 having taken place, as the thimbles are 

 all alike, and any one forms a symmetrical 

 termination to the organ. Whatever pur- 

 pose the rattle may serve in the snake's 

 economy and its use is still involved in 

 some obscurity it undoubtedly does not rep- 

 resent the owner's age, nor the sum total of 

 his manslaughter." 



Energy in Organic Evolution. In two 



papers, Mr. John A. Ryder has endeavored 

 to demonstrate the potency of energy as a 

 factor in organic evolution, and to show that 

 the form of the hen's egg is determined by 

 mechanical means while the egg membranes 

 and shell are in process of formation within 

 the oviduct. The development of the figure 

 of eggs is regarded by him as a purely dy- 

 namical problem, or one in which energy 

 is applied in a definite manner to a mass 

 in statical equilibrium within the oviduct. 

 The moment motion is set up to propel the 

 egg through the duct the forces operative 

 in determining the figure of the as yet un- 

 formed shell depend upon the physiological 

 activity and condition of tone of the muscu- 

 lar walls of the oviduct. 



Cremation of Cholera-dead. From a pa- 

 per read by Dr. Robert Newman before the 

 Northwestern Medical and Surgical Society 

 of New York in favor of the cremation of 

 persons dying of cholera, it appears that 

 there are now fifteen crematories in this 

 country, and that two thousand and seven- 

 teen incinerations took place between 188*7 

 and 1892, of which eight hundred and sixty- 

 eight were at New York. The Earl Memo- 

 rial Crematory, at Troy, is the most costly. 

 Thirty-two active cremation societies are 

 scattered over the country. Nearly all those 

 who participated in the discussion of the pa- 

 per agreed with the author as to the impor- 

 tance of cremation in cholera. In respect 

 to the objection the only really important 

 and valid one that has been made that cre- 

 mation facilitates the concealment of crimi- 



