204 BOTANICAL GAZETTE [APRIL 
fatty acids shorten the after-ripening period of both hawthorn and 
apple. 
Mlle. Promsy also used acetic acid with good results on seedlings 
of tomato and corn. She studied (4'7, 48) the effect of acids on 
the respiration of germinating seeds of tomato, corn, barley, Dios- 
corea, and Elaeis guineensis. She finds that organic acids (citric, 
malic, oxalic, tartaric, and acetic) increase the respiratory quotient 
and at the same time the intensity of respiration, measured by 
evolution of CO,. Inorganic acids, on the other hand, do not 
modify the quotient, except in the single case of the fatty seeds of 
Elaeis. Seeds were soaked in a solution of the acid for 24-48 hours, 
then put in germinative conditions in sand, and the sand watered 
with the solution. Seedlings submitted to the action of organic 
acids grew more rapidly than the control, increased more in wet 
weight, and increased more in dry weight, if determined at the end 
of the germination period when the plants were green. . Seeds 
treated with inorganic acids, HCl and H.SO,, germinate more 
quickly than the control. The wet weight of seedlings is increased, 
dry weight is the same as the control. 
MartIN FiscHer (12) found that acids greatly increase the 
absorption of water by colloids, while salts decrease the absorption. 
He studied the absorption of water by gelatin, fibrin, and frog 
muscle. 
A certain degree of acidity seems to be necessary before germi- 
nation of Crataegus seeds. The acidity of the hypocotyl develops 
very slowly and little water is absorbed in the early stages of after- 
ripening. It was thought that absence of free acids might be the 
limiting factor to growth. An attempt was made to supply this 
by soaking the seeds in acid before putting them in after-ripening 
conditions. 
METHOD OF TREATMENT WITH ACIDS 
Seeds of Crataegus, with carpels removed but testas intact, 
were soaked in the acid solution over night at 5° C., washed, and 
put on moist cotton in Petri dishes. At the end of 14 days they 
were washed carefully, the coats removed, and the embryos washed 
in distilled water. They were then tested for presence of free 
enzymes. In the accompanying table (IV) the results are given 
