106 JAMES G. HUGHES, JR. 
position as the ordinary striated fiber, from which the electro- 
plax is derived. Accordingly the following stains were applied: 
(1) Van Gieson’s picro-nigrosine, which stains muscle a 
yellowish-green and connective tissue blue, mixed as follows: 
To 45 cc. of saturated aqueous solution of picric acid, 5 ce. 
of 1 per cent aqueous solution of nigrosine were added, the whole 
mixed thoroughly. Paraffin sections of the electroplaxes (ver- 
tical) fixed in pure corrosive sublimate were stained for 12 hours 
in this mixture; then washed in picric alcohol, dehydrated 
rapidly, cleared and mounted. <A description of an electro- 
plax is as follows: The jelly electric tissue stained blue. The 
electroplax proper with its three layers stained a yellowish- 
green. The rods were just visible, and were stained the same 
color and to the same degree as the electroplax. The fact 
therefore that the rods stained the same color as the electro- 
plax and as muscle shows that they are very probably com- 
posed of some muscle-like substance. It may be noted here 
that the electroplax proper always stains about the same as 
voluntary muscle, a control consisting of voluntary muscle hav- 
ing proved the truth of this statement several times. The 
reason for this is apparent when we recognize the fact that the 
electroplax is derived from a striated muscle fiber. This stain 
also confirms the results of Weigert’s resorcin-fuchsin stain 
that the rods are not composed of any kind of connective tissue, 
and also indicates decidedly that the jelly electric tissue is white 
fibrous connective tissue. The controls used were the adductor 
muscle from an oyster, the ligamentum nuchae of a_ horse, 
and the white fibrous connective tissue in the umbilical cord 
of a sheep, all being stained exactly the same period of time as 
the electroplax. 
(2) Van Gieson’s picro-fuchsin, which stains muscle yellow 
and connective tissue red, was mixed as follows: To a satu- 
rated solution of picric acid were added a few drops of a sat- 
urated aqueous solution of acid fuchsin, until the mixture 
became a deep red. The stain was then ready for use. (It 
may be noted that, if too much acid fuchsin be added, muscle 
as well as connective tissue will stain red). 
