Harta, Nature of the Pericellular Network. 141 
nique were used. The paper is accompanied by a large num- 
ber of drawings made from his own preparations. In some 
cases, he noticed a direct continuation of the pericellular net- 
work by way of terminals with the medullated nerve fibers. 
Thus he proves conclusively that one set of structures forming 
the pericellular network is composed of the terminals of the 
axones, and, in other words, this particular network is nervous 
in nature. BETHE (00) also showed a direct continuation of 
his ‘‘primitive neurofibrils’’ into the Golginetz. BETHE here 
used his own molybdenum technique. It is therefore evident 
that the weight of opinion is in favor of the nervous nature of 
the network and against the view of APATHY. 
Another objection to the view of HELp has been raised by 
BETHE (00). Although he agrees with HeELp in considering 
the pericellular network to be composed of the terminals of the 
axones represented by the primitive neurofibrils, yet he does 
not accept the delicate meshwork structure formed by the 
union of the side branches of the axone terminals as well as 
the presence of the neurosomes. HELp’s answer to this criti- 
cism is not a satisfactory one and demands further evidence. — 
My own results obtained from the studies on the preparations 
stained with a new technique, reveal several facts which support 
very strongly HeEtp’s idea as well as my own observations pre- 
viously published ('03), and are opposed to the views of 
ApATuy and BETHE. 
The staining reagents used for the present investigation 
were prepared by the following way : 
Minced sheep’s brains were boiled in 10% formalin for 
several days on the water-bath. The solution was filtered 
off while hot. A concentrated aqueous solution of ammonium 
molybdenum in excess was added together with a few drops of 
HCl and the solution boiled again. The solution is at first 
yellow and then turns to a blue color. After continued boiling 
(at least 24 hours) an intense blue color is produced. The na- 
ture of the substance which gives the blue color has not yet 
been determined. The preparation is stained with the blue so- 
lution thus obtained, in the following way: The materials are 
