Recent and Fossil Conifera. 141 



more frequent than the regular form of the meshes, throughout 

 the whole transverse section ; whereas, in a tree of the same 

 species, from the British Colonies in North America, the regular 

 quadrangular form of the meshes was as predominant as in any 

 species of the pine tribe I have ever examined. To acquire a 

 thorough knowledge of the structure of any kind of wood, a 

 single section of small dimensions will by no means suffice ; and 

 some of those who have lately attempted to instruct the world 

 with regard to the difference between fossil and recent coniferae, 

 have done themselves no credit, and the world some injury, by 

 drawing conclusions from a single, and that too imperfectly cut, 

 section. 



In some of the junipers as well as in the Thujae, the quad- 

 rangular form of the meshes very generally prevails ; but per- 

 haps the greatest irregularity in this respect is to be seen in the 

 Araucarias. In this tribe the meshes are seldom much larger in 

 one direction than another ; but even when they approach the 

 quadrangular form, the partitions are often less rectilinear than 

 in many of the true pines, and the meshes from the centre to 

 the surface are more uniform in size than in any of the pines, 

 the process of vegetation having sustained no regular annual in- 

 terruptions. 



Besides these differences in the form, &c. of the meshes, there 

 is a peculiarity in the Araucarias which I have not observed in 

 any one species of the coniferous family. The peculiarity con- 

 sists in an unusual weakness or want of tenacity in the concen- 

 tric partitions. This weakness is such that with every care, 

 and with the keenest edged instrument, it is scarcely possible to 

 cut a transverse section of any considerable size, without the 

 medullary rays separating from each other. To procure even 

 a very small slice with the radial partitions in a state of ad- 

 hesion, it is necessary to place the edge of the instrument pa- 

 rallel to the medullary rays, and to press it forward in that di- 

 rection ; for if it be made to move in a diagonal direction, which 

 in general is the best direction for making a very fine slice, 

 scarcely two rays will be found to adhere to each other. Hence 

 we may infer, that the timber of the Araucarias, if the whole 

 species be similar to that from Moreton Bay, must be greatly in- 



