Vol,. 8, 1922 CHEMISTR Y: JOHNSON A ND BROWN 
187 
of the sense organs accompanies regeneration of the nerve, one would expect 
to find the first regenerated sense organ in the region of the regenerated 
nerve. At fifty-six days there was evidence of regeneration in the sense 
organs and it occured very near the region of the regenerating nerve. 
Following the lateral-line posteriorly beyond the cut the first two sense 
organs in this region had not regenerated, but on the site of the third sense 
organ regeneration of the supporting cells had occured. Next followed a 
degenerated sense organ after which came a regenerated one, indistinct in 
outline, but with three or four sensory cells. Continuing beyond this 
there were no more regenerated organs. 
Ninety-eight days after cutting the nerve regenerated sense organs oc- 
cured in consecutive positions. The sense organs regenerate element by 
element as they degenerated. The supporting cells differentiate before the 
sensory cells do. The completely regenerated sense organs appear quite 
normal. 
From the above data it may be concluded that degeneration of the 
lateral-line organs in Amiurus occurs within fourteen days after cutting 
the lateral nerve and that regeneration of these organs takes place after 
fifty-six days. 
Olmsted, J. M. D. 1920a. The nerve as a formative influence in the development 
of taste buds. /. Comp. Neur., 31, (465-468). 
Olmsted, J. M. D. 1920b. The Results of Cutting the Seventh Cranial Nerve in 
Amiurus nebulosus (Lesueur). J. Exp. Zodl., 31, (369-401). 
THE ISOLATION OF PYRIMIDINES FROM THE NUCLEIC ACID 
OF TUBERCLE BACILLUS 
By Trkat B. Johnson and Ei.mhr B. Brown 
DEPARTMENT OF Chemistry, Yai.e University 
Communicated May 23, 1922 
This paper is a preliminary announcement of results which have been 
obtained in an investigation of the nucleic acid of tubercle bacillus. This 
research was supported in part by funds provided for the work by the 
National Tuberculosis Association. The raw material employed in the 
research was obtained through the cooperation of Dr. Esmond R. Long 
of Sprague Institute, Chicago, Illinois. 
With the quantity of tubercle bacillus placed at our disposal it has been 
possible to isolate the nucleic acid in sufficient quantity for hydrolysis and 
to make an accurate determination of the pyrimidines contained therein. 
We find that this nucleic acid is characterized by the fact that it does not 
