June I, 1882] 



NA TURE 



107 



P. ovata, (id.) 



P. Dixoni, Bowerbank 



P. Bcrwerbankii, Can. . 



Seven species of pine are known from our British 

 Eocenes. They are enumerated here for the first time : — 



P. Prestwickii, sp. nov. mini ) Woolwich 



P. macroctphalus, (Lind. and Hutton) > and Reading 



\ Beds. 



( Bracklesham 

 j to Bembridge. 

 I London Clay 

 ) to Bracklesham. 



P. Plutoni, Baily \ Eocene of 



P. Graingeri, id / Antrim. 



I am not sure that the two latter may not be identical 

 with species already described abroad, but they seem 

 distinct from the other British species. 



It will be remarked that all the English species are 

 from marine or estuarine deposits, and it is a singular fact 

 that no trace whatever of leaves or fruit of the Abietineae 

 have been found in those plant beds of freshwater origin 

 in England, which have recently yielded such exceedingly 

 rich floras. It is equally strange that all our Eocene 

 cones from the London clay and strata beneath have 

 been imbedded before shedding their seed, while those 

 from the Middle and L T pper Eocenes are gaping arid 

 seedless. If inference upon such slender ground were 

 permissible, it would seem as if those that were imbedded 

 during the cooler Lower Eocene period had grown near 

 to where they were imbedded, and their leaves may yet 

 be found in our little-known Lower Eocene floras, while 

 those that were imbedded during the hottest Eocene 

 periods had drifted a long way. The well-ascertained 

 absence of pine foliage during the Middle Eocene in 

 England, and the constantly-decayed condition of the 

 cones, are the data upon which this view may be grounded. 

 Farther north, at Antrim, as we should anticipate, the 

 cones seem more perfect. 



It appears desirable to test the relative length of time 

 that ripe and unripe pine cones, seeds and foliage will 

 float, especially in sea-water, and the length of time 

 required to reduce them to the decayed condition of the 

 Barton and Bracklesham specimens, and it is to be hoped 

 that some one possessing facilities, will undertake experi- 

 ments. 



It will also be interesting to trace out why cones so 

 frequently fall in a closed unripe condition. A Bourne- 

 mouth resident writes to me that it takes three years for 

 the cone to come to perfection, and that if it remains on 

 the tree all that time, the scales open wide as it hangs, 

 beginning at the base, and making a plainly audible 

 crackling noise as they separate. This occurs chiefly on 

 sunny summer days. The seeds being liberated, either 

 fall or are picked out by tom-tits. 



CEDRUS. — Only four species, or varieties according to 

 some, are known — the Himalayan, Lebanon, Atlas, and 

 Cyprus cedars. The cones are globose and erect on the 

 upper side of the branches. The scales are thin, leathery, 

 and closely pressed together, and persist for some time 

 after the seeds are shed. The cones break up on the 

 trees, and fall piecemeal, the scales falling separately, 

 except near the apex, where they remain together as a 

 rosette. This habit may account for the absence of fossil 

 cedars in the Tertiaries, the older forms from the Green- 

 sand of Shanklin and Maidstone having possiblypossessed 

 a different habit. 



Picea has twelve to twenty-four species. The leaves 

 are solitary, acicular, and more or less in two rows, while 

 the cones somewhat resemble those of the cedar. They 

 inhabit temperate regions throughout the northern hemi- 

 sphere, almost to the confines of vegetation. Two Gault 

 forms from Hainault are doubtfully referred to the genus, 

 while fossil species are met with in Iceland and Green- 

 land, the Wetterau, the amber-beds, and a few other 

 Miocene localities. 



TSUGA possesses five species. The leaves are not rery 

 different to those of Picea, and the cones are like those 



of Cedrus. but pendent and terminal, persisting for several 

 years, and with scales more loosely imbricated and per- 

 sistent. They inhabit Japan, the Himalayas, and North 

 America, and have been found fossil in the same beds as 

 Picea. Piiuis Crameri, Heer, related to Tsuga, is the 

 most widely-spread fossil in the Arctic Cretaceous. 



Pseudotsuga has only one species, inhabiting from 

 Mexico to Oregon. 



Abies contains eighteen species. The scales are 

 leathery, loosely imbricated, and fall with the seeds and 

 the leaves, as in Tsuga. It extends over the northern 

 temperate regions of both hemispheres, chiefly in moun- 

 tainous districts. It is known from the Wealden, and 

 even Jurassic, and from Greenland, Iceland, and in 

 European Miocenes. 



Larix possesses seven to ten speries. The cones are 

 small, with leathery persistent scales, and fall in clusters 

 with the dead branches. The leaves are linear, solitary, 

 or in bundles, and deciduous in all but one species. The 

 larch extends over the colder regions of Europe, Asia, 

 and America. But four fossil forms have been noticed — 

 three from the Miocene of Francfort, and one from 

 Austria. 



The Abietineae in the existing state in northern regions 

 of Europe, Asia, and America, outnumber the broad- 

 leaved trees bv ten to one, for pine-barrens in Noith 

 America stretch 300 to 500 miles uninterruptedly, and, in 

 the Old World, form a nearly continuous belt from Scan- 

 dinavia to the east coast of Asia. 



Some grow to gigantic size. Sections from two 

 American species of Abies, two of Picea, and one of 

 Pinus, have been exhibited, and officially stated to have 

 been cut from trees considerably over 300 feet in height. 

 In the Himalayas, the cedar and Pinus excelsa exceed 

 200 feet, and other species almost rival these, and even 

 in Europe the heights of several species have been stated 

 at from 120 to 180 feet. The greatest longevity ascribed 

 to any of the Abietineae belongs to the cedars, which have 

 been estimated at from 600 to 900 years old. 



Many of the species are exceptionally hardy, and pass 

 the Arctic circle, and the larch in Siberia extends, as a 

 trailing shrub, to latitude 52°. In Mexico, pines grow at 

 an elevation of nearly 13,000 feet, and in Central Asia, of 

 10,000 feet. 



The economic value of the Abietineae surpasses that of 

 all other forest-trees, and they supply a very large propor- 

 tion of the timber in use. Their wood is valuable for all 

 purposes, and some of it is of immense durability, while 

 the money value of that imported into England alone is 

 9,000,000/. per annum, exclusive of other products, such 

 as pitch and tar, which reach nearly another million. The 

 nuts of some species of pine are used as food, and the 

 bark, woody fibre, and secretions are more or less utilised 

 in different countries, and for most varied purposes. Only 

 one species of the whole family is indigenous to England, 

 Pinus Sylvestris, the common Scotch pine, the larch and 

 the spruce having been introduced, though both were, I 

 believe, indigenous here in the Pliocene age. 



J. Starkie Gardner 



THE BRUSSELS CHROXOGRAPH 



OX November 18, 1880, a description was given in 

 Nature of certain great galvanic chronographs 

 which were then being constructed by Messrs. E. Dent 

 and Co., of the Strand and Royal Exchange, London. 

 The second of these instruments— that for the Royal Ob- 

 servatory of Brussels — has now been completed. The 

 arrangements for pricking upon the chronograph barrel 

 are much improved, and as they overcome a serious con- 

 structive difficulty, we propose to give some account of 

 them. 



It will be remembered that the main feature in the 



