SUITED FOK PLANTING. 291 



greyish, brownish, or reddish ■coloured limestones and clayey 

 marls, which occur in the muschelkalk, lias, Jura, and in the 

 more recent formations. 



2. The loamy, yellow dolomitic limes, yielded by the grey, 

 yellow, brown, or blackish dolomitic limestones a,nd maris occur- 

 ring in the Triassic and Jurassic systems. 



3. The more stoneij varieties arising from the imperfect decom- 

 position of the light grey limestones, which are found more or 

 less in all the above-named formations, but especially in the 

 muschelkalk. 



1. Tlie clayey limes are binding, earthy, less stony, moderately 

 deep, strong mineral soils, which, when kept well in shade, are 

 fresh, mild, and fertile. As it is binding, the oak is not in 

 general found thriving as well on this variety, although single 

 stems may occasionally grow to a good size. For example, 

 during last summer we found an oak (Strahlenheiiner Forst bei 

 jSTordheim) on shallow Muschelkalk resting on a subsoil of moder- 

 ately cleft and tilled lime blocks, which at 4 feet from the 

 ground had a girth of 33 feet, or 10 i ft. in diameter, and was 

 still growing well. The clayey limy soils formed by the clayey 

 marls, on the other hand, are less binding, and hence more suited 

 for the growth of oak timber. 



2. The yellow loaviy dolomitic limes are usually deep, mild, less 

 binding, and fresh, so that they offer a favourable soil for the 

 oak, except on such places as are rendered shallow by horizontal 

 blocks of limestone forming the subsoil. Less favourable to the 

 growth of this tree than the dark, fertile varieties of hunter 

 sandstein, the dolomitic limes are better able to nourish the oak 

 than the more binding limes and clays can be. 



3. The more stony varieties are poor, shallow, less earthy, and 

 dry, and are decomposed with difficulty — they want moisture 

 and depth, and the idea of rearing oak timber on these should not 

 be entertained. 



Clayey and Marly Soils. — Throughout the rocks of the Mesozoic 

 period deposits of slatey clays, potter's clay, and marls frequently 

 occur imbedded among the limestones and sandstones, especially 

 forming the transition from the one kind of rock to the other. 



1. The Slatey clays, of a red colour from the presence of ferric 

 oxide, and having a finely laminated structure, are chiefly met 

 with in the hunter sandstein formation. Such clays are also 

 often seen in the Carboniferous system, but then they are dark- 

 coloured and bituminous, having much in common with the 

 more recent clays, (e.g. of the Keuper), which we have termed 

 yjotter's clay. The former varieties yield on decomposition a 

 loose, red, friable, not a binding or plastic clayey soil, some- 

 times deep, at other times shallow, and often dry. Where 

 the latter is the case, the oak does not find a home. By the 



