P OP ULAR MIS CELL ANY. 



711 



tinents, but to include also what are now ex- 

 tremely rare and even local genera. These 

 results opened up a new channel for inves- 

 tigating the problem of distribution, and it 

 was first entered by Dr. Asa Gray, who pur- 

 sued it with brilliant results. Professor 

 Blytt, of Christiania, in his essay on " The 

 Immigration of the Norwegian Flora during 

 Alternately Rainy and Dry Periods," invoked 

 the glacial period to account for the disper- 

 sion of Arctic plants, dealt with a rising land, 

 and assumed that immigration took place 

 overland, as Mr. Forbes had done in the case 

 of British vegetation ; but he also found an- 

 other powerful controlling agent, in alter- 

 nating periods of greater moisture and com- 

 parative drought, of which the Norwegian 

 bogs afford ample proof. The phenomena 

 of distribution in the southern hemisphere 

 are more difficult of explanation. The so- 

 called Antarctic flora is now confined to the 

 mountains and southern islands of the tem- 

 perate zone, nowhere crosses the parallel of 

 62", and is uniform around the globe. The 

 temperate flora is fourfold, presenting more 

 differences as between the three continents 

 and New Zealand than do the floras of the 

 northern continents. These plants have 

 their representative species and genera on 

 the mountains of the tropics, each in its 

 own meridian only, and there meet immi- 

 grants from all latitudes of the northern 

 hemisphere. No direct proof has been dis- 

 covered that the southern plants originated 

 in the south, but reasons exist for supposing 

 that the southern flora came from the north 

 temperate zone. Mr. Thistleton Dyer has 

 maintained that the floras of all the coun- 

 tries of the globe may be traced back at 

 some time of their history to the northern 

 hemisphere, and that their present peculiari- 

 ties in affinity and specialization are the nat- 

 ural results of the conditions to which they 

 have been subjected during recent geologi- 

 cal times, and supports his view with plau- 

 sible arguments. A very similar view has 

 been held and published by Count Saporta in 

 his essay " L'aneienne Vegetation polaire." 

 Mr. Wallace independently advocates the 

 view of the northern origin of the floras and 

 faunas of the world in his " Island Life." 

 The later works on geographical distribu- 

 tion include Mr. "Wallace's " Geographical 

 Distribution of Animals," Professor A. de 



Candollc's " Geographic Botanique," Dr. 

 Grisebach's "Die V6g6tation der Erde," 

 and Mr. G. Bentham's addresses before the 

 Linmean Society in 1869, 1870, and 1872. 



Indian Burial - Caves. Dr. Edward 

 Palmer, who has been working under the 

 direction of the Peabody Museum of Archae- 

 ology of Cambridge, Massachusetts, has ex- 

 plored several caverns in Southwestern Coa- 

 huila, Mexico, that were long ago used as 

 burial-places by the Indians. These caves 

 have been mentioned by a few writers, and 

 stories have been told by people who visited 

 them or heard of them, nearly half a cen- 

 tury ago, of the immense number of mum- 

 mified human bodies that they contained. 

 Since then the caves have been worked for 

 niter, and thousands of the mummies have 

 been burned. Dr. Palmer has found a con- 

 siderable number of the bundles undis- 

 turbed, and has brought them to Cambridge. 

 Each bundle contains the bones of one or 

 more human skeletons and ornaments, im- 

 plements, small baskets, articles of cloth- 

 ing, and other objects. The resemblance 

 of the mummies with those found in the 

 caves of Kentucky and Tennessee is of par- 

 ticular interest. Among numerous objects 

 of art from the collection which Dr. Palmer 

 exhibited at one of the meetings of the Bos- 

 ton Society of Natural History were parts 

 of a fringed skirt, on the edge of which 

 feathers had been fastened ; a feather head- 

 dress, braided sandals, and pieces of finely 

 and evenly woven cloth in different-colored 

 patterns. Many of the things are not like 

 those used by the Indians of the present 

 day ; and not a thing derived from Europe- 

 ans has been found, so far as can be learned, 

 in any of the caves. Dr. Palmer therefore 

 thinks that the bodies were placed where 

 they were found long before the Spanish 

 conquest of the country. 



Hope for Sufferers by neart-Disease. 



According to Dr. J. Milner Fothergill, the 

 views of the medical profession as to the 

 prospects for the future of cases of val- 

 vular disease of the heart are undergoing 

 very considerable changes, in a direction 

 opposite to the hopelessness with which 

 they have been regarded in the past. Not 

 every murmur which may be heard over the 



