288 SEMI-CENTENNIAL OF TORREY BOTANICAL CLUB 
(about I gram per 50 c.c. nutrient solution) takes place. Simul- 
taneous cultures in Kavalier Bohemian and quartz flasks did not 
exceed a yield of about 0.3 grams per 50 c.c. nutrient solution 
unless zinc was added. 
According to Lepierre (5, 6), on the other hand, the increased 
yields obtained by Coupin should be ascribed to the excessive 
volume of nutrient solution employed as compared to the volume 
of the containing flask. The increased depth of the solution, he 
assumes, results in decreased aération of the cultures and increased 
growth ensues. Zinc, it is stated by Lepierre (6), could be found 
neither in the flasks (whether Jena or Kavalier is not stated) or 
compounds used nor in the fungal membranes. 
Javillier (4), in repeating Lepierre’s experiments in Kavalier 
glass, did not succeed in obtaining an essential variation in the 
yield by varying the ratio of surface to volume. 
It is interesting to note in this connection that the presence 
of zinc in Jena glass has frequently been reported in the literature, 
more recently through the analyses of Nicolardot (7) and of 
Walker and Smither (12). Moreover, Kavalier Bohemian glass 
according to the same authors is free from zinc. 
That the composition of the cultural flasks is of importance 
and that both the rate of growth and the fructification of Asper- 
gillus niger can be influenced by solution of components of the 
glass has been claimed by Benecke (т). 
To obtain, if possible, additional evidence as to whether 
cultures of A. niger to which no zinc has been intentionally added 
attain a greater growth in Jena glass than in Kavalier Bohemian, 
I have grown parallel cultures in these two glasses, and in addition, 
a third glass, Pyrex. Zinc according to Walker and Smither (12) 
does not enter into the composition of Pyrex glass. 
In the experi ts wl d iption follows the Pfeffer nutrient 
solution has been used (ro). 
PFEFFER SOLUTION 
ЖЕТ ата quM АА aires Cle C. d 1000.0 
Синеаман 22 тес ане 50.0 
Ammonin nitrates, s оом v ne 10.0 
Mono-potsssium phosphate... -oo oda 2...2... ve 5.0 
Padme АКА o oon olo sx or ш. 2.5 
ТОИ ОЕЕО ео Me trace 
