STUDIES IN THE PHYSIOLOGY OF THE FUNGI 
V. Tue Свомтн or Certain Func Іх Puant Decoctions 
B. M. DUGGAR, J. W. SEVERY, AND H. SCHMITZ 
In a previous paper attention has been drawn by the 
writers! to the growth relations of certain fungi in a few plant 
decoetions with and without additional nutrients. In the con- 
tinuation of this work much the same methods have been fol- 
lowed, but the number of fungi employed has been reduced 
to two, the one, Aspergillus niger, being taken as a repre- 
sentative of saprophytie species, and the other, Gloeosporium 
(Glomerella) Gossypii as a representative of parasitic forms. 
Besides the decoctions previously employed, namely, bean, 
sugar beet, prune, potato, turnip, and eorn meal, there have 
been used also decoctions of apple, mangold (mangel-wurzel), 
celery, carrot, and salmon. Basing the decoctions as before 
on 00 grams of the dry weight of the material used per liter 
of water, the fresh weight quantities of the additional ma- 
terials involved were as follows: apple, 294.1 gm.; carrot, 
438.2 gm.; mangold, 546.4 gm.; and celery, 333.3 gm. In the 
ease of the salmon it was not practicable to determine the 
amount of material required on a dry-weight basis, so that 
one сап, 1515 oz. (439.4 gm.) net, was used for a liter of water. 
As far as possible the oil or fat was eliminated. In the ease 
of the celery untrimmed bunches were employed. In each 
instance the product was cut into small pieces, a liter of water 
added to the required green weight of product, and this was 
steamed for one hour at 15 pounds in an autoclave, then fil- 
tered hot through Canton flannel, and finally made up to the 
proper volume. After stock flasks were arranged the solu- 
tions were autoclaved for 20 minutes at 15 pounds pressure. 
Titrations of these decoctions showed the following reaction in 
terms of Fuller’s scale: apple, +14.5; carrot, +14.5; celery, 
+10.5; mangold, +15; and salmon, +43. As mentioned later, 
however, little weight is attached to these values. 
1 Duggar, В. М., Кадес J. W., and Schmitz, Н. Studies in the physiology 
of the fungi. IV. e growth of ‘certain fungi in plant decoctions. Ann. М 
Bot. Gard. 4: 165-173. f. 1-4. 1917. 
ANN. Мо. Вот. GARD., Vor. 4, 1917 (279) 
