ELECTROPLAX OF ASTROSCOPUS 103 
confirmed the evidence as presented by Mallory’s stain in re- 
spect to the composition of the rods; that is, they are not white 
fibrous connective tissue. 
I now undertook to apply stains which were tests for elastic 
fibers, and the first under this head is Weigert’s resorcin-fuchsin 
stain in which connective tissue according to Weigert and other 
writers stains dark blue. The stain was made up as follows: 
One per cent of basic fuchsin and 2 per cent of resorcin were 
dissolved in water; 50 ec. of the solution were raised to the 
boiling point, and 25 cc. of liquor ferri sesquichlorate P.G. 
were added and the whole boiled with stirring from 3 to 5 min- 
utes; a precipitate was formed. After cooling, the liquid was 
filtered, and the precipitate which remained on the filter was 
boiled with 50 ec. of 95 per cent alcohol. It was then allowed 
to cool, filtered and the filtrate made up to 50 ce. with alcohol, 
and 1 ec. of hydrochloric acid added. 
Paraffin sections of the electroplaxes fixed in corrosive sub- 
limate were stained for 6 hours in the above alcoholic solution 
of the precipitate. They were then washed in 95 per cent 
alcohol, dehydrated quickly, cleared and mounted. <A descrip- 
tion of the results are as follows: The electroplax proper, with 
its three layers, did not take the stain at all. The jelly electric 
tissue around the electroplax stained a brillant blue. The 
rods contained in the electric layer of the electroplax were 
invisible. The fact therefore that the rods did not take the 
stain at all shows they are not composed of elastic connective 
tissue. The control used in this case for elastic tissue was a 
section of the ligamentum nuchae of a horse, which, when put 
in the stain for exactly the same time as the electroplax, came 
out a deep blue. The ligamentum nuchae was chosen as a con- 
trol since it is, perhaps, the best known and best representative 
of elastic tissue found in the animal kingdom. 
Not desiring to rely solely on the above stain to prove that 
the rods are not composed of elastic tissue, the electroplaxes 
were treated with the digesting fluid, pepsin, and the results 
noted. Vertical sections of electroplaxes, having been freed 
from paraffin, were put for 3 minutes in a very weak solution 
