Page:Enquiry into plants (Volume 1).pdf/69

 of special differences between individual kinds; and after that we must take a wider range, making as it were a fresh survey.

Some plants grow straight up and have tall stems, as silver-fir fir cypress; some are by comparison crooked and have short stems, as willow fig pomegranate; and there are like differences as to degree of thickness. Again some have a single stem, others many stems; and this difference corresponds more or less to that between those which have sidegrowths and those which have none, or that between those which have many branches and those which have few, such as the date-palm. And in these very instances we have also differences in strength thickness and the like. Again some have thin bark, such as bay and lime; others have a thick bark, such as the oak. And again some have smooth bark, as apple and fig; others rough bark, as 'wild oak' (Valonia oak) cork-oak and date-palm. However all plants when young have smoother bark, which gets rougher as they get older; and some have cracked bark, as the vine; and in some cases it readily drops off, as in andrachne apple and arbutus. And again of some the bark is fleshy, as in cork-oak oak poplar; while in others it is fibrous and not fleshy; and this applies alike to trees shrubs and annual plants, for instance to vines reeds and wheat. Again in some the bark has more than one layer, as in lime silver-fir vine Spanish broom onions ; while in some it consists of only