34 ANNALS OF SCOTTISH NATURAL HISTORY 



very .different configuration of the land from that of the 

 present in this part of Scotland, as a considerable amount of 

 shelter would be necessary for such trees to attain this size. 

 A curious remark is made in this connection by the author 

 of the account of the island in the Old Statistical Account, 

 -the Rev. Archibald M'Coll, where he says that it is not 

 probable that trees would now thrive on the island upon 

 trial, " the situation being so far in the ocean and without 

 shelter." As to the kind of tree which formed the wood, I 

 think the larger ones at least were probably oak. Evidence 

 not being forthcoming that these remains were used for 

 torches, makes it unlikely that they were conifers, as such 

 trees were generally put to this use in the Highlands. Mr. 

 Maclean tried to grow willows. He says : " They grow all 

 right in summer, but wither from the tops in spring" ; and 

 he adds : " I think the cold strong winds are the cause." A 

 few years ago the Marquis of Lome sent seeds of Pinus 

 Pinaster, which were sown on the sandhills in one place, 

 but the young plants were not protected from the cattle and 

 sheep, and have since died (" A Vertebrate Fauna of Argyll 

 and the Inner Hebrides," 1892). 



Sandy shores and dunes surround the greater part of 

 the island, muddy shores being rare. This gives a pre- 

 ponderance to certain plants, while some usually common 

 species are limited in their distribution. 



The geological formation of Tiree is mainly Lewisian 

 gneiss, similar to that of its neighbour Coll, and to the Outer 

 Hebrides, but dissimilar to that of the other parts of the 

 Inner Hebrides, with the exception of part of lona. The 

 flora also would appear to correspond more with that of the 

 Outer Hebrides than with that of the Inner, at least of those 

 islands from Mull to Skye inclusive. Omitting the island 

 of Coll for the present, there are certain characteristic 

 plants common to Tiree and the Outer Hebrides which are 

 believed to be absent from the Inner Hebrides from Mull 

 to Skye. These are Ranunculus Drouetii, R. Baudotii, 

 Hippuris vulgaris, Apium nodiflorum^ which occurs as the 

 var. ocreatuju, A, inundatuin, Veronica Anagallis-aquatica, 

 Potamogeton pectinatus, P. filiforjiiis, Cliara aspera, C, Jiispida. 

 They are all aquatic or sub-aquatic, some being sub-maritime, 



