350 Barber. — Cupressinoxylon vec tense. 
the decomposition of spruce-timber by Polyporus borealis 1 ; 
and the far from rare occurrence of hyphae in the specimens 
shows that some fungus had been at work before petrifaction. 
The case referred to is exactly analogous to the decaying 
bordered pits of a piece of rotten Sorbus Aucuparia described 
by Kraus, where the inner circle increased in diameter 
according to the stage of decay until it fused with the 
outer 2 . What at first sight was regarded as a remarkable 
variability in the bordered pits was thus found to be due 
to the state of preservation of the specimen, and all measure- 
ments made in such parts were subsequently disregarded. 
The inner pore, which is circular, is not usually well 
preserved in the specimens. The average of a number of 
measurements in the best places was 3-5 //, these limits 
being rarely passed. 
More detailed results were obtainable with the outer 
border. Many hundreds of measurements were taken with 
a view to determine whether, as in recent woods, any clearly 
marked increase could be noted in the size of the pits from 
the pith outwards. The small pits in the summer wood were 
left out of consideration. 
The results are as follows : — 
Greatest diameter of Bordered pits. 
Branch (1), 3rd ring, 7-0 n; 5th, 9.5 /*; 6th, 11.3 ju ; 7th, 14-0/4. 
Branch (2), 3rd ring, 8-4/4; 4th, 10-5/4; 5th, 12*8/1; 8th, 14-0/4. 
Ditto in another section, at intervals, 9-7, 10-3, n-i, 12-0, 12*2, 13*7/4- 
Root (2), successive rings, 10-5, 13, 13, 13.3, 13*2, 12-5, 12*7, 14, 13*5/4. 
Root (2), successive regions, 10-4, 12*2, 12*3, 13-6, 13 /4. 
These figures show how incompletely a single number 
would suffice to express the size of the pits. From our 
knowledge of their varying size in different organs, and 
in the same organ at different ages, we should expect to 
1 Hartig, The Diseases of Trees, English Edition, Fig. 124. 
2 Kraus, Mikrosk. Unters. 
