10 



NOMENCLATURE 



tia; mar go thallodes spurius of Lecidea petraea; peridium 

 spurium of iEcidium. 



12. 



Terms taken from common life remain without any ex- 

 planation, when they are used with no variation of their 

 usual meaning : otherwise, they must be more exactly defin- 

 '^^d. Thus, pilosus, in technical language, means something 

 different from the idea suggested by it in the usual written 

 language. In this latter use, it means the hairy condition in 

 general ; but, in the former, it denotes particularly the pre- 

 sence of soft hairs, somewhat bent. 



CHAP. II. 



CHARACTERISTIC EXPRESSIONS FOR FORMS AND 



QUALITIES. 



13. 



' We enumerate under this title, those terms which relate to 

 the properties of the organs, or parts of plants, and we seek, 

 especially, to make those terms general, in order to avoid all 

 repetition. It ought to be remarked, that we are only fur- 

 nishing an introduction to the comprehension of the works of 

 o£her writers, and that we do not, therefore, take upon us, 

 to answer for the correctness and necessity of every term. 



I. Measure of the Parts. 

 14. 



We call the measure of the parts absolute, when it has a 

 reference, not to any comparison with other parts of the same 

 plant, but to some other commonly assumed scale. The mea- 

 sure is relative, when we compare the extension of one part 

 with the size of others, belonging to the same plant. 



