148 Proceedings of Indiana Academy of Science. 
of the unaired plant. This was made necessary by the greater transpiration 
and growth activities of the plant which was aired in the way mentioned. 
The air used to aerate the specimen of Avena sativa as well as the others 
mentioned in this paper was propelled by the Kekulé apparatus. 
In like manner air was passed through a Sachs culture solution in which 
were growing seedlings of Brassica alba. Here again the aired specimen 
showed a great advance over the unaired plant. When the plants were two 
weeks old the aired specimen was 12 cm. high, while the unaired specimen 
was 5 cm., high. The roots of the unaired specimen were rather few and 
long, while those of the aired specimen were aggregated more into a mass 
of considerable size, were much denser and more numerous and the total 
length many times greater. The aerial portion of the aired plant was not 
only taller but more than twice as broad. The leaves of the aired plant 
were much larger and broader and more numerous and the transpiratory 
activity as in Avena sativa was much increased. The comparative difference 
in size of the aired and unaired specimens of Brassica alba was a little 
greater as the measurements will show, than the difference in size of the 
Avena sativa plants. .The dried weight of the aired specimen of Brassica 
alba was 110 mg. while that of the unaired specimen was 25 mg. 
Seedlings of Pisum sativum were grown in a Sachs nutrient solution as 
the above mentioned specimens some of which were aired and some not 
aired. Here again the aired specimen grew fastest and best. When twenty 
days old the aired seedlings were 85 cm. high and the non-aired 41 em. high. 
The dry weight of the aired plant was 2.5 grs. while that of the unaired 
plant was 0.5 gr. In this experiment the aired specimen was nearly twice 
the height of the unaired plant while the dry weight exceeded that of the 
unaired five times. 
Other experiments on Fagopyrum esculentum and on Helianthus annuus 
gave similar differences. The plants of Fagopyrum esculentum especially 
showed decided differences. Those specimens that were aired formed flow- 
ers profusely two weeks sooner than the specimens which had not been 
aired. 
In addition to the above experiments which is only an outline of part of 
the work done, Miss E. G. James is at present working on an extended 
series of experiments on aeration of plants under my direction. She has 
invented several new and necessary pieces of apparatus for carrying out 
the work under different conditions. Experiments performed by her on 
Lactuca sativa confirm my experiments and also extend them in various 
ways. 
