Of late yeals numerous acclimatization socie ties have been formed (the best known of which is the So•i(t6 d'Acclimatation of Paris), having as their object the transference of de sirable animals from their native lands to other parts of the world where they may thrive to human advantage. This has been found feasible in many instances, so far as the ability to be come acclimated is •nneerned, hut in many eases the expected benefits have turned to evils through o•.brmultiplication or other means of becoming a local pest, and such experiments are now rarely attempted. The introduction of sal inonoid fishes from the Pacific to the Atlantic side of the United States, and from Europe to New Zealand, of bumble-bees into New Zealand, and of several insects, such as ladybirds, as enemies of agricultural pests, are instances of the more beneficial sort. The European house-spar ro• in North America, the mungoos and agna toad in the \Vest Indies, the rabbit in Australia, and a great host of more or less accidentally introduced insects dest•uctiVe Of plants, et e., ace cases of an opposite eharaeter. For particulars in respect to three. See accounts of the respective animals.
lv PE“PLE. This treats of the ability of men to maintain themselves in a country with radically different climatic conditions from those from which they migrate. At present the inevitable tendency of European and American peoples to spread over the majgar part of the earth gives the question many practical bearings. Can a race and a civilization from the temperate zone be transplanted to the tropics? The question is a double one (1 ) Can individuals from the tem perate zone live in the tropics for a few years and maintain their health and vigor; (2) can they work at their usual occupations, maintain their customary vigor, energy, and ability, rear families and propagate their kind for several generations? On the first point most authorities agree in the affirmative, provided reasonable provision for sanitation is made, and temperance and thrift prevail among such emigrants. On the second point authorities differ, with the bal. anee in the negative. Races differ in their abil ity to adjust themselves to new climatic condi tions. The individual or the race may not suc cumb at once when transferred to a very differ ent climate, and yet the acclimatization may be only partial. Certain organs only of the body may be affected by the changes, so that "diseases of acclimatization" may be induced. Thus Euro
peans are liable ill tropical countries to suffer from diseases of the liver, while natives of the tropics are subjected to pulmonary troubles ill temperate zones. The African in the United States has a high death rate from lung affections. On the other hand, loss of hardihood induced by climate may express itself mainly in deteriora tion in size, as is the ease with the Shetland pony. So far as the human races are concerned there seems to be a direct ratio between intelli gence and capacity for acclimatization. The An glo-Cerinan race is able to endure elimatie changes with less loss of vigor than any other European race. and for this reason has been able to surpass all the others as colonizers. High moral qualities are needed. Homesick ness is a frequent cause of failure. Temperance and thrift are excellent qualities for success, as evidenced in the history of Jewish and Chinese emigration. Mankind is tolerant of great ex tremes of climate, —97' F. to 1:14° F. being the greatest extremes recorded as having been en du•ed by human beings, though no such range of variation has ever been endured by one peo ple or in any one place. Not only temperature but also meteorological conditions have an ef fect. and moisture is. next to temperature, the most important element.
Iltnt.toctt.trtty. The best general treatment of acclimatization may be found in .1. Hann. Hand buch der Mininlologir (Stuttgart, 1S97) ; Da• win, 7'he Variations of .1 nimals and Plants der DOM e1i iralion. revised edition (London.
s75) ; Pavillard, Eh:m(111s biologic ( Pa ris, 19U1 ) ; /7/onzrugeogropbic ysiolagisrlo r aru ad la ye (Jena, 1s98) ; llollick, "Itelation Between Forestry and Geology in New Jersey," Geological Surrey of Neu. Jersey, Annual Report (Trenton, 1899) ; Wallace, Island Life (London, ISSO) ; Heilprin, The Geographical and Geological Distribution of Animals (New York, 18S7) ; Wallace, The Geographical Distri bution of Animals, 2 volumes (London, 1896). A popular treatment of acclimatization of peoples is given in Ripley, Racial GeOraphy of Europe (Boston, ISO])), in which book there are also excellent bibliographical references; also A. Ire land, Tropical Colonization (New York, 1899) ; Peschel, The Races of Man and Their Geograph ical Distribution (London, 1878).