116 O. LARSELL 
Ponzio (’06) has described and figured fibers in the lung 
parenchyma which he designates as interalveolar, intercellular, 
and intracellular nerve filaments, respectively, and he also 
describes an intracellular nerve reticulum. Ponzio employed the 
5 
Fig. 7 Sensory nerve terminations in the wall of an atrium. Rabbit R1, 
series;H3. 62u. Camera lucida. X 880. 
methylene-blue and Cajal methods of staining on the lungs of 
newborn kittens and puppies. 
In my preparations, both those stained with methylene-blue, 
and those prepared by the pyridine-silver method, there exist 
fibers and filaments which closely resemble those illustrated by 
Ponzio and in corresponding positions. I am inclined to believe 
that they are elastic fibers rather than nerve fibers. This 
