40 HUMPHREY 
Other stock solutions were made up in which the amounts of 
the various salts used in a normal solution were reduced in 
quantity one fourth and one eighth, though the quantity of dis- 
tilled water was kept the same, 500 c.c., in all the solutions. 
It will be noticed that from one solution the acid salt, potassium 
phosphate, was left out with a view to testing its value as a 
stimulus to germination. Spores of the same lot were sown in 
the various solutions the same day they were collected; the cul- 
ture dishes were carefully covered and placed on a north window- 
sill where a uniform amount of diffused light fell upon each 
culture. In another dish that had been paraffin-coated, water 
that had been twice distilled was placed and on the same date 
spores of the same lot were sown. ‘These germinated in con- 
siderable numbers within twelve days. Some of the water used 
in this culture was taken from the supply bottle and evaporated 
on a slide. On examination, a precipitate of organic particles 
was found, showing that certain compounds had passed over 
with the water in distilling, and it was thought probable that 
these acted as a stimulus, for the spores in this culture germi- 
nated before those in the culture containing none of the acid 
salt. In fact these latter seemed to show no indications of any 
preparation for germination, such as change in color of exospor- 
ium from very dark brown to a lighter more translucent shade. 
The distilled water used in the preparation of the various cul- 
ture solutions was from the same stock bottle as that used in the 
distilled-water culture. Why spores collected at the same time 
and sown at the same time on these two media should have 
germinated earlier in distilled water containing organic impuri- 
ties than in a culture solution void of one of its constituent salts 
is difficult to account for unless in the latter we have a physio- 
logically unbalanced solution which has been shown by Loeb? 
to exercise a certain toxic effect upon certain marine and fresh- 
water animals and by Osterhout’ in his experiments upon alge. 
This, however, needs far more extensive investigation than has 
yet been given to it. 
1Loeb, 1905: Pfliiger’s Archiv, 107: 252. 
2 Osterhout, 1906: On the Importance of Physiologically Balanced Solutions 
for Plants. University of California Publications. Botany, Vol. 2, No. 10, pp. 
229-230. 
