THE FARMER'S MAGAZINE. 



477 



cij^al part of the matter the mass consists of, are 

 Calluna vulgaris, Erica tetralix, Andromeda poli- 

 folia (which latter only grows on bogs in the cen- 

 tral counties of Ireland), Juncus efFusus, J. 

 conglomeratus, J. acutiflorus, J. uliginosus, Erio- 

 phorum vaginatum, Molinia coerulea, Aira caespi- 

 tosa, and Pteris aquihna. These combined con- 

 stitute the woody and fibrous portion ; whilst the 

 bog mosses Sphagnum cymbiforme, S. squarrosum, 

 Polytrichum commune, with several species of 

 Hypnura and the Lichens Cenomyce rangiferina 

 and C. uncialis, form the greater part of the soft 

 spongy portion, which retains moisture and ulti- 

 mately consolidates into turf. 



A few more species of grasses 'besides those 

 already mentioned also grow on this kind of bog, 

 such as Airaflexuosa, Agrostis alba,Triodia decum- 

 bens, Holcus moUis, and H. lanatus. The trunks 

 of trees which often occur in such abundance 

 on this kind of bog consist of Scotch fir (Pinus 

 sylvestris), oak (Quercus robur), birch (Betula 

 alba), alder (Alnus glutinosa), and hazel (Coryhis 

 avellana). The oak is found for the most part near 

 the margins of the bog, with the roots resting on 

 the clay or marl bottom, whilst the firs extend 

 further towards the centre, and their roots gener- 

 ally rest on several feet of bog, thus affording proof 

 of a considerable deposit of vegetable matter having 

 taken place before they vegetated on it. Judging 

 from the roots and trunks found, the trees appear 

 to have grown to a large size, when, by natural 

 decay, or probably by storms, and often by fire, 

 they fell and became covered over by the gradual 

 growth of the bog, until sufficient matter accumu- 

 lated for seedling plants growing over and above 

 them. In this way the pines appear to have died 

 out, and to have been replaced by younger plants, 

 according as the bog increased in growth up to the 

 present surface, there still being a few surviving 

 trees of the ancient stock growing on the Earl of 

 Arran's property in the county of Mayo. The 

 finding of those roots and trunks at different 

 elevations, the one frequently placed above the 

 other, has led some persons to suppose there have 

 been distinct and successive growths of those 

 forests, some of which consisted partly of species of 

 trees not found now in Ireland ; but, so far as my 

 investigations have gone, I have not perceived any- 

 thing that could warrant such a conclusion being 

 come to. 



It is stated by Mr. Babington that the late 

 Profesor Don referred some cones sent to him 

 from Irish bogs to Pinus Mughus, which circum- 

 stance has been quoted by M. De Candolle in his 

 late work " Geographie Botanique ;" but those who 

 are best acquainted with the varied appearances of 

 the cones of the common Scotch fir, as they grow 



on contiguous trees in the same forest, will con- 

 sider the instance noticed as only very slight proof 

 of Pinus Mughus ever having formed part of the 

 timber found in our bogs. Although it appears to 

 be a settled fact that the Norway spruce (Abies 

 excelsa) once grew in England, where it died out, 

 and has not reappeared in a natural state, there 

 exists no proof of that species ever having grown 

 in Ireland. The Irish bog formations would seem 

 to be of a more recent date than the time of the 

 glacial epoch of geologists, excepting probably that 

 of Lough Neagh, and it would be very hazardous 

 to state what particular species some of the 

 fossihzed wood belonged to, which is found there. 

 Abundance of the common yew and some moun- 

 tain ash are frequently found in those bogs at 

 great depths under the surface, both of which grow 

 naturally in many parts of Ireland at present. 

 Willow, holly, and the common white thorn are the 

 only other kinds of trees whose trunks are found 

 of any considerable dimensions in our bogs, and 

 they all grow naturally on those curious drumlins 

 and eskars which occur so frequently near bogs. 



A variety of compact black bog is to be found at 

 a higher level than any of the former kinds men- 

 tioned. This covers large tracts on the slopes of 

 the mountains at considerable elevations above the 

 sea level, and affords excellent turf for burn- 

 ing. It seems to have increased very slowly, 

 especially where the drainage is free; but in the 

 level basins where water lodges it is frequently of 

 great depth, and increases fast. The plants which 

 are now growing on the surface, and appear to 

 have mainly contributed to form the peat on the 

 latter, are Juncus squarrosus, Eleocharis crcspitosa, 

 Calluna vulgaris, Erica tetralix, Nardus stricta, 

 Carex stellulata, C. caespitosa, with the sphagnums 

 and hchens already specified, and Jungermannia 

 juniperina in the southern and western counties, all 

 of which mix with the woody branches of the 

 heath and the running roots of the Junci, causing 

 them to decay into a mass of decomposed vegetable 

 matter. On the drier slopes, where the fall is so 

 great as to prevent water from lodging, the best 

 kinds of peat earth for horticultural purposes are 

 found, particularly on sandstone formations, where 

 the debris of the rock enters largely into the com- 

 position. The plants which generally prevail on 

 this kind of bog are Calluna vulgaris. Erica cinerea, 

 Empetrum nigrum, Vaccinium myrtillus, V. vitis 

 idcea, Andromeda polifolia (the latter in Connemara 

 only), Aira flexuosa, Potentilla tormentilla, with 

 Hypnum squarrosum, H. Schreberi, Racomitrium 

 lanuginosum, and Cenomyce rangiferina, which, 

 combined in a state of decomposition, constitute 

 the principal part of the mass. 



The last variety of bog which I shall particularly 



