408 Horne and Williamson. — The Morphology and 
5 . Peptone and Glucose. 
Flasks (capacity 50 c.c.), containing 25 c.c. each of a solution made up 
to contain 2 per cent, peptone and 4 percent, glucose, with an initial pH 5-0 
and total acidity equivalent to 34 c.c. N/i NaOH per litre, were inoculated 
with the three species and kept at 20° C. Observations were made as in 
the case of peptone after fourteen days’ growth. 
Result: 
E. catenulata . Considerable thick growth of a somewhat leathery 
consistency and very much wrinkled : colour white to grey and buff: both 
macrospores and conidia present, but the latter not numerous. Ammonia 
not detected. Solution acid to litmus ; strong yeasty smell emitted. 
pH 4-2. Total acidity equivalent to 56 c.c. N/i NaOH per litre. 
E. viridescens. Growth similar in character to that exhibited by 
E. catenulata , but less bulky. Surface growth cream-grey. Macrospores 
numerous: conidia not observed. Ammonia present, but litmus blues 
slowly. Solution acid to litmus. Strong odour of coco-nut oil emitted. 
pH 4*6. Total acidity equivalent to 40 c.c. N/i NaOH per litre. 
E. acremonioides. Much submerged growth : surface growth meagre, 
thin, greyish white in colour: mycelium white, tough : incipient hyaline 
macrospores present ; conidia not observed. Ammonia not detected. 
Solution acid to litmus. pH 5*1. Total acidity equivalent to 30 c.c. 
N/i NaOH per litre. 
6. Asparagin. 
With E. catenulata , E. viridescens, and E. acremonioides very little 
growth occurred in 1 per cent, asparagin made up in distilled water. The 
growth was comparable to that in distilled water without asparagin. The 
growth obtained when E. catenulata and E. viridescens were grown in 
solutions containing 1 per cent, asparagin and 4 per cent, glucose was 
comparable to that obtained when these species are grown in 4 per cent, 
glucose without asparagin. When, however, mineral salts are present in 
addition to glucose and asparagin, the reactions occurring are similar to 
those obtained when these fungi are grown in peptone alone, viz. the 
solution becomes alkaline and ammonia is liberated. 
B. Growth Limitation in Relation to Hydrogen-ion Concentration. 
For the investigation of growth limitation on the acid side, N/10, N/100, 
and N/1000 solutions of HC 1 made up with distilled water, and solutions 
of neutralized potato extract and potato extract agar, to which the acids 
were added in similar concentrations, were used. The pH values of all the 
media thus prepared were determined, after autoclaving, by the electrical 
method. By this means a series of media having a wide hydrogen-ion con¬ 
centration range was obtained. For these experiments the two species, 
