108 JAMES G. HUGHES, JR. 
men away.) It was then placed in a freshly prepared solution 
of silver nitrate, made as follows: 
To 20 cc. of 1 per cent silver nitrate solution, two drops of a 
40 per cent solution of caustic soda were added. A gray pre- 
cipitate was formed. Twenty to thirty drops of strong am- 
monia were then added—just enough to dissolve the precipitate. 
The tissue was allowed to remain in this for 45 minutes; then 
washed in distilled water containing a few drops of glacial 
acetic acid (25 drops of acid to 100 ce. of water). It was left 
in this for about 10 to 15 minutes, until the reddish-brown 
color had changed to yellowish-brown. It was then washed 
in distilled water, and placed for 12 hours in 1 per cent hydro- 
quinone containing 5 per cent neutral formal. It was again 
washed with distilled water, dehydrated, and imbedded in 
paraffin through chloroform. The tissue was then cut and 
sections mounted with balsam. 
A description of a vertical section of an electroplax so stained 
is as follows: The electroplax proper stained a very light brown. 
The nuclei, staining a little deeper, could be clearly seen. The 
electric connective tissue did not stain at all, and was not even 
visible. The nerve endings, which were very abundant, stained 
dark brown or black, thus being clearly differentiated from 
the rest of the electroplax. The rods could not be found. If 
present, they must have stained light brown, the same color 
as the electroplax, for they certainly were not present as nerve 
endings, which as I noted above, stained a dark brown or black. 
This conclusion therefore is evident, that the rods are not nerve 
endings of any kind. 
The fact therefore that these fibers and rods have been shown 
to be composed of a muscle-like substance brings up a new 
kind of muscle fiber to the attention of histologists. These 
fibers have not been shown to be contractile, are non-striated, 
dense and exist without any apparent connection with each 
other. In view of the above facts we cannot give to these ele- 
ments of the electroplax any other function except that of sup- 
port, and this will consequently have to suffice until some other 
investigator presents a better interpretation. 
