1. Mossornas spridning. 



»The spores of Mosses and Hepaticae are so minute that 

 they must be continually carried through the air to great distan- 

 ces, and we can hardly doubt that, so far as its powers of diffu- 

 sion are concerned, any species which fruits freely might soon 

 spread itself over the whole world». 



»Here then we have a group in which there is no question 

 of the means of dispersal; and where the difficulties that present 

 themselves are not how the species reached the remote localities 

 in which they are now found, but rather why they have not esta- 

 blished themselves in many other stations which, so far as we can 

 judge, seem equally suitable to them». 



Uessa ord af A. Ptussel Wallace i bans »Island Life^ (sid. 

 344) angifva den synpunkt, som vid en teoretisk betraktelse sy- 

 ncs bora blifva den bestammande, om man vill utreda orsakerna 

 till mossverldens nuvarande fordelning. Mossornas sporer iiro 

 finare och mangfaldigt lattare an den vulkaniska askans partik- 

 lar, om hvilkas vidstrackta spridning genom luften intet tvifvel 

 rader. Den 30 mars 1875 foil i Stockholm och natten forut i 

 Upland, Dalarne och Norge pimstensaska, som icke hade kunnat 

 komma fran nagon narmare belagen vulkan an den 1860 kilome- 

 ter aflagsna Myvatnsorafi pa Island, hvars utbrott hade borjat den 

 29 pa morgonen, berattar min van Th. Thoroddsen i sin »Over- 

 sigt over de islandske Vulkaners Historic » (sid. 119). Ar 472 

 skall askan fran Vesuvius hafva blifvit af vinden ford till det 1200 

 kilometer aflagsna Konstantinopel, hvarom lases i Marcellini kro- 

 nika (J. Roth, Der Vesuv, Berlin 1857, sid. 4). Likasa berattas 

 om Tomboros bekanta utbrott 1815, att askan af motpassaden 

 drefs till det 1900 kilometer aflagsna Amboina (Hann, Handbuch 

 der Klimato logic, Stuttgart 1883, sid. 389). Det mest storartade 



