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NOTICES OF AUTHORS. 



The coniferae differ much in the internal arrange- 

 ment of their woody structure from the hard wood 

 species, having tissue of much larger cells, and be- 

 ing generally destitute of the large lineal tubes, 

 which in hai'd wood constitute the more porous in- 

 ner part of the annual layer. When these tubes 

 occur in the pines, they also differ in position, being 

 in the outer part of the layer. Owing to the resin 

 of the pines becoming fixed in the cells of the outer 

 part of the annual layers, inspissated, w^e think, by 

 the summer's heat and drought (others say congealed 

 by the cold), these cells are filled up, and this part 

 of the growth rendered much denser than the in- 

 ner part of the layer, being from solidity semi-tran- 

 sparent. We woidd attribute the abundance of 

 resin in the Georgian pitch pine to the heat and 

 long summer of that country, probably in concert 

 with damp richness of soil, not only occasioning this 

 deposit under these circumstances, but perhaps in- 

 ducing a disposition in this species to the formation 

 of this product The absence of the Jlise^ tubes, 



* The climate of a country in regard to annual steadiness, 

 can be pretty accurately determined by the appearance of the 

 annual layers of trees, especially of the pine tribe ; and in a new 

 settlement where great difference of size of layer, and of resinous 

 deposit is observed, we may be pretty certain the seasons are not 



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