296 BOTANICAL GAZETTE [OCTOBER 
took place in the M/10 and in the M/50 media, a change which was 
more marked in the former. The cloudiness due to the undissolved 
calcium carbonate had entirely disappeared and the medium had 
become slightly brownish. This seemed to indicate some chemical 
change by which acid had been formed which dissolved the CaCo,, 
and also a slight decomposition of the dextrose. Later analyses 
indicated that a loss of nitrogen in some form-may have accom- 
panied this change. In the other solutions no such change took 
place, indeed the cloudiness increased rather than decreased, due 
no doubt to loss of carbon dioxide during the boiling. This showed 
that the change above mentioned was due to the high concentration 
of the ammonium nitrate. 


TABLE X 
CULTURES IN VARYING QUANTITIES OF AMMONIUM NITRATE AS INDICATED 
: Amount in each az 
No. Mol. wt. concentration co gl 3 culture nitrogen 
(50 cc.) mg. 
mg. 
Bere a 8.0 400.0 140.19 
ae .. ' 80.0 28.04 
RR es ee oun 0.32 16.0 5 
ee a ec ek 0.06 3-2 By np 
ST Oo sk ts 0.0128 0.64 0.22 






Two fungi were used for these cultures: Fusarium and Mycelt- 
ophthora. Analyses were made of the latter only. The cultures” 
were allowed to develop from April 17 to June 5, oF 48 days: 
Vigorous and characteristic growth took place in all the cultures of 
th fungi. 
The Fusarium produced the characteristic pink coloration of 
the medium, the degree of color depending on the amount of growth. 
At first the M/250 showed the best growth, but later this was sur 
passed by the M/so, and finally the best growth was in the M/r0, 
although M/to and M/so showed but little difference. As 
previously stated, no analyses were made of thisform. — 3 
The growth of Myceliophthora differed in the fact that the best 
growth both at the first and at the end was in the M/25°0 solution. 
Also the mycelium, at least in the higher concentrations, developed 
a small amount of purple color on the surface of the mat, while the | 
