386 CHIKANOSUKE OGAWA 
between these three kinds of fibers in a five to six-month child 
as follows: ‘‘The reticular fibers in the mouths of the alveolar 
ducts and alveoli enclose the elastic fibers spirally and hold them 
tightly together. The elastic fibers in turn almost always ac- 
company the muscle fibers. Several of the spiral reticular fibers 
accompany the elastic fibers which extend from the elastic rings 
of the alveolar ducts into the alveolar walls.” . 
Now, sections from the above-mentioned animals were stained 
first by Bielschowsky’s method and then for only a few minutes 
with resorcin-fuchsin, because this stain is deleterious to the 
silver precipitation. It was found that although the reticular 
fibers always accompany the elastic fibers at the mouths of the 
alveolar ducts and alveoli, there was a relation contrary to that 
described by Russakoff. The spiral reticular fibers are included 
within a sheath of elastic fibers and where there are few elastic 
fibers they enclose only the side of the reticular fibers nearest 
the lumen. 
The thicker elastic fibers and the thicker reticular fibers which 
branch from the fiber rings into the alveolar wall always accom- 
pany one another, with the elastic fibers constantly superficial 
to the reticular fibers. This does not hold true for the finer 
branches. 
Russakoff states that elastic fibers always accompany muscle 
fibers, but he does not describe them in detail. I investigated 
the preparations in which elastic fibers and nuclei of muscle 
fibers were stained, and found that the elastic fibers are likewise 
situated superficial to the muscle fibers. 
The remainder of the article is devoted to the relation of 
reticular and muscle fibers. In Bielschowsky’s method the 
reticular fibers are stained so deeply that the nuclei of the muscle 
fibers are concealed in the mouths of the alveolar ducts and 
alveoli. By van Gieson’s picrofuchsin method both the nuclei 
and fiber rings are seen, although the fine reticular fibers are not 
stained. It is clear by this method that the nuclei of the muscle 
cells are usually located more deeply than the reticular fibers 
and sometimes they are situated side by side. 
