CONIFERAE. 83 



gations extensively instead of intensively. It is difficult to see the use of 

 descriptions of all sorts of fragments of wood from the collections, though 

 they may include hundreds of exotic species, so long as we are ignorant of 

 the limits of variation within the species and the individuals. Far more 

 profitable would be a comparative examination of a few species based on 

 abundant material from all parts of the plants, for this alone can give that 

 sure foundation without which our conclusions are precarious and oftentimes 

 in the air. Such a mode of proceeding would be all the more obvious, 

 because the value of the whole of these laborious investigations would be 

 very doubtful, if the statements before us were shown to be strictly correct. 

 According to Schroter, all species of Abies, with two exceptions, belong by 

 the structure of their wood to Cedroxylon, Abies Welbiana only agreeing 

 with Cupressoxylon and A. Pindrow with the first sub-form of Pityoxylon. 

 In this sub-form he also places Pinus longifolia, Roxb., while all other pines 

 belong to the second and third sub-forms. If this is so, how can we expect 

 to conclude with any show of justification from the anatomical structure of 

 woods that they belong to any particular divisions of our system ? And it 

 is as a rule only slightly probable that we shall find pieces of wood in actual 

 connection with leafy branches and cones, though this may happen once now 

 and then. The only instance known to me in which this method of deter- 

 mination was pursued is supplied by Schenk l . He found in the lignites of 

 Wurzen in Saxony large cones and leafy branches of Sequoia Couttsiae, 

 Heer, and with them larger branches and stems, and he determined the 

 connection of the latter with that species on the strength of their agreement 

 in structure with the leafy branches. Felix 2 subsequently decided that the 

 woody fragments belonged to Cupressoxylon Protolarix, Gopp. 



According to the statements of authors, Kraus 3 especially, Taxoxyla 

 are at present known only from the Tertiaries^ Cupressoxyla have been 

 found in the Chalk, Pityoxyla and Cedroxyla as far down as the 

 Keuper. Araucaroxyla and Pissodendra are the only woods which 

 occur in the older formations, if we put out of sight the two doubtful kinds 

 from the Coal-measures known as Pinites Conwentzianus, Gopp. 4 , and Peuce 

 Withami, Lindl. and Hutt. 5 The latter is referred by Renault to Araucaro- 

 xylon, by Kraus to Cedroxylon. The figure would allow of either con- 

 clusion ; Kraus' view implies that the specimen is a piece of wood from the 

 root. Only fresh examination of the original can decide the question. To 

 Araucaroxylon belong also the pieces of wood described by Dawson c from 

 the Middle Devonian beds of Canada and New Brunswick, Dadoxylon 

 Ouangondianum, D. Hallii, D. Newberryi and Ormoxylon Erianum G. and 

 S. N. The latter may be considered from the character of the pith to 



1 Schenk (5). 2 Felix (1). 3 Schimper (1). 4 Goppert (6). 5 Lindley and Hutton (1), 

 vol. i, tt. 23, 24. 6 Dawson (1). 



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