RECORD: STRUCTURE OF CERTAIN WOODS 259 
indistinct, and the most satisfactory results can be secured by 
counting the vessel segments. In the Zygophyllaceae the lines, 
though very uniform and readily visible under the lens, are so 
very closely spaced (about 250 per inch) that is it practically im- 
possible to make an accurate count without the use of the com- 
pound microscope. By using low power and reflected light the 
smooth surface of a small specimen can be readily examined and 
measurements made without preparing thin sections. 
Considerable variation in tier-height was found not only in 
different specimens of the same species but also in the same speci- 
men. Even within a given inch of length the number per quarter 
may show a variation of from two to five as a result of the occa- 
sional to frequent bifurcation of the tiers, with consequent narrow- 
ing at the point of branching. The greatest variation in tier 
height within a species was noted in Diospyros virginiana L., 
where the counts per inch on eleven different specimens were as 
follows: 57, 57, 58-60, 60, 61, 62, 63, 66-68, 70-72, 72-74, 81-82; 
a maximum difference of 25 per inch, or nearly 45 per cent on the 
basis of the minimum. In only one other case did the variation 
exceed 20 per cent, and almost always it was less than 10 per cent. 
In 86 woods of the Leguminosae the number of markings per 
inch were as follows: under 100, 29 per cent; 100 up to 125, 34 
per cent; 125 up to 150, 21 per cent; 150 to 190, I2 per cent. 
Nearly every wood showing between 125 and 190 “ripple marks”’ 
per inch belongs to the Leguminosae. The investigated woods of 
the Zygophyllaceae have considerably more than 200 per inch, 
mostly about 250, and may, by means of this feature alone, be 
readily separated from all of the others. This fact has proved of 
practical value in distinguishing the wood of true lignum-vitae 
from its various substitutes. 
The present investigation fails to confirm certain findings of 
other writers. Von Hdhnel (1, p. 38) states that the rays are 
storied in Parkinsonia, but there was no evidence of this in the 
specimens examined by the writer. The grenadillo wood is re- 
ferred to as “Inga vera W.?” (p. 39) but this is probably incor- 
rect, inasmuch as various specimens of Inga spp. were found to 
be without any tendency to storied structure. The name “ grena- 
dillo’”’ is applied to several woods, one of which is Brya Ebenus DC. 
Another wood with “ripple marks” was provisionally identified 
