PROFESSOR EDWARD FORBES. 91 



of Man ; for instance, on tlie southern cliffs, about Peel Castle,* on the 

 sands to the north of Ramsey, f and at Maughold,J remarkable also for 

 its rock scenerj', and for its antiquities. There is a deficiency, however, 

 of some southern and south-eastern maritime species, as might be 

 expected fi'om climatal considerations, withoiit reference to any geograph- 

 ical changes. But, confining oiu'selves to the inland, it will appear, 

 upon the whole, that the Isle of Man, like other small isolated tracts of 

 country, is rather limited in the number of its plants, and Forbes was 

 led to philosophise on this point. There appears to be reason to suppose 

 that the island was not isolated fi-om Ireland till (geologically speaking) 

 modern times, and he thought that this agreed with the extension to 

 Man of certain (so-called) Lusitanian species, which he names, Pin- 

 guicula lusitanica, Scirpus Savii, &c. ; and also that the absence of certain 

 southern species, if it is not from climatal inadequacy, may likewise be 

 set down to an analogous cause, the separation of the outer islands, 

 whilst England still made part of the Continent, thus allowing such 

 plants to extend themselves in it, but not further. As regards truly 

 mountainous — or what is tantamount — northern species, the above 

 absence or paucity holds good, but from another cause. In the main 

 islands some of these have been supposed to have survived glacial times 

 by their fixity on the summits of high mountains, elevation being tanta- 

 mount to latitude and lower temperature. Perhaps the Manx hills were 

 never very high, but, it may be, half submerged, and receiving their 

 deposits of clays and di'ifts, whilst those of Scotland and Wales were 

 the seats of glaciers. 



With this floral deficiency it is rather interesting to observe how many 

 plants, which are not truly indigenous, have ^escaped from'ancient home- 

 steads and gardens, and have become quite at home, as well as 

 luxuriant ; showing that islands and isolated places often grow in great 

 perfection plants which are not native, when once introduced. Horticul- 

 turists are aware of this proclivity of the island. Such interlopers are 

 the following: — Spircea salicifolia, Senecio saracenicus, Inula Heleniiun, 

 Gnaphalium viargaritaceum, Pyrethrum Balsamita, Balsamita inilgaris,^ 

 Lavatera maritima. Antirrhinum Orontium, Reseda fruticulosa, Saponaria 

 officinalis, Myrrhis odorata, Petroselinum sativum, Tinea major, and, perhaps, 

 other plants of a similar origin. The Irish arbutus, hydrangea, fuchsia, 

 myrtle, ilex, euonymus, jasmine, escalonia, Buddleia, and tree-veronicas 

 are very luxuiiant in the open air. The cowslip appears to be absent, 



♦ Spergula maritima, Cerastium tetrandrum, Chenopodium inurale, 

 Arenaria mirina, Hyoseyamus niger. At the Stack of Scarlet, Samohcs Vale- 

 raiidi, and JEnanthe crocata. 



f Salsola Kali, Eusc7is aculecttus, Cakile maritima, Cramie maritima 

 Olaux maritima. Convolvulus Soldanella, and Tamarix. 



I Critlimum tnaritimum, Scilla verna, Silene maritima, Allium vineale, and 

 Asplenium marinum. After a storm, enormous fronds of Laiiiinaria bulbosa 

 L. saccharina, and A. esculenta are cast on the shore ; these deep-water Fuci are 

 most productive of iodine, which, however, can only be here manufactured to pay 

 when the drug is high in price. 



§ Costmary, or Ale-cost, smelUng strongly of spearmint, but bitter. It was 

 formerly used in brewing, and was introduced from Italy more than three centuries 

 ago. It grows about old cottage enclosures, and the Manx call it sweet-leaf. Unless 

 seen in flower it somewhat resembles Pyrethrum Balsamita, called camphor-plant, 

 which is quite naturalised. 



