Walter de Gruyter, Berlin / New YorkHolzforschung - International Journal of the Biology, Chemistry, Physics and Technology of WoodSTREIT, W, FENGEL, D. 1994. Heartwood formation in quebracho Colorado: Tannin distribution and penetration of extractives in cell walls. Holzforschung 48: 361–367....
Only a few Palaeozoic ammonoids show mature modi- fications of the shell; it can be assumed that they have kept growing throughout their lives producing new chambers as they grew or, having been r-strategists, true adults were just rather rare. A number of species show evidence for a ...