A CONFUSION OF TECHNICAL TERMS IN THE STUDY 

 OF WOOD STRUCTURE. 



By C. D. MEhh. 



The anatomical structure of wood is essentially a technical sub- 

 ject. The pivotal point in this study is the correct knowledge of 

 the elements composing wood, and inseparable from this knowl- 

 edge are the names of these elements. In other words, as the 

 student is acquiring a definite notion of wood elements he ought 

 to have a name that will be definite, approximate and above all 

 constant. At the same time there should be a clear limitation or 

 line of demarkation between certain elements that are sometimes 

 difficult to distinguish, as, for instance, between wood fiber and 

 tracheids, or between tracheids and vessels. 



There are at present no text books dealing especially with this 

 subject, though numerous authors have written extensively along 

 lines relating to it. No two writers agree absolutely in termin- 

 ology. The majority of investigators differ so widely that it con- 

 stitutes a very serious hindrance to students. In the^days of the 

 early plant anatomists, Grew and Malpighi, who worked with 

 very defective microscopes, there was an excuse for this widely 

 differing nomenclature, for the reason that no two observers 

 saw the same thing exactly alike. At present, however, the mi- 

 croscopes have reached such a degree of perfection that there 

 should be no difficulty for all investigators to see the structure 

 of elements exactly alike. Now is the time to remove the bar- 

 riers that perplex the student, for the condition of nomenclature 

 is such that it will greatly depreciate or even preclude effective 

 work of beginners. A number of terms now used are obsolete, 

 unscientific, and unnecessary. The student is obliged to devote 

 much time learning what certain names mean. Of course, all 

 names are more or less arbitrary, but any particular name should 

 be associated with only one kind of wood elements. At present 

 the student does not find, for example, that the term tracheae is 

 constantly associated with elements having their abutting ends per- 

 forated, but also with elements known as tracheids having both 

 ends closed. This confusion of names is true especially in the 



