Кораловий острів

Chapter 30

           Thoseofthethirdclassarethelowcorallineislands,usuallyhavinglagoonsofwaterintheirmidst.Theyareverynumerous.

           "Astothemannerinwhichcoralislandsandreefsareformed,therearevariousopinionsonthispoint.Iwillgiveyouwhatseemstomethemostprobabletheoryatheory,Imayadd,whichisheldbysomeofthegoodandscientificmissionaries.Itiswellknownthatthereismuchlimeinsaltwater;itisalsoknownthatcoraliscomposedoflime.Itissupposedthatthepolypes,orcoralinsects,havethepowerofattractingthislimetotheirbodies,andwiththismaterialtheybuildtheirlittlecellsorhabitations.Theychoosethesummitofavolcano,orthetopofasubmarinemountain,asafoundationonwhichtobuild,foritisfoundthattheyneverworkatanygreatdepthbelowthesurface.Onthistheywork.Thepolypesonthemountain-top,ofcourse,reachthesurfacefirst;thenthoseattheouteredgesreachthetopsoonerthantheothersbetweenthemandthecentre,thusformingthecoralreefsurroundingthelagoonofwaterandthecentralisland.Afterthat,theinsectswithinthelagoonceaseworking.Whenthesurfaceofthewaterisreached,thesemyriadsofwonderfulcreaturesdie.Thenbirdsvisitthespot,andseedsarethusconveyedthither,whichtakerootandspringupandflourish.Thusarecommencedthosecorallineisletsofwhichyouhaveseensomanyintheseseas.Thereefsroundthelargeislandsareformedinasimilarmanner.

Налаштування
Фон сторінки
Розмір шрифту
Міжрядковий інтервал
Фразові дієслова
Показати / Приховати меню
Шрифт
Roboto Lora
Уведомления
Сторінка 319 з 370