1920] 



NOYES 6* WEGHORST— ROOTS 



333 



on four dates, February 1, 9, 23, and March 27. The plants were 

 harvested April 15 and the roots removed April 20, 1918. 



The roots of the plants grown in the pots that had received the 

 carbon dioxide gas applications the previous year had the mal- 

 formations attributed to carbon dioxide in the previous paper. 

 Where the soil had never been subjected to carbon dioxide treat- 

 ments, the roots were well spread and extended considerably into 

 the soil. Where carbon dioxide had been applied, the roots were 

 shorter, spread out horizontally just beneath (o" to 2") the surface 



Fig. i. 



treatments 



soil were o, 8, and 24 hours per day. 



of the soil, and had tap roots that were abnormally short, crooked, 

 and branching. The data with the fertilizer treatments are given 

 in table I. The results show that something was left in the soil, 

 due to carbon dioxide gas additions to the soil the previous year, 

 which both shortened the tap roots and the distance below the 

 crown at which the roots curved or split up into smaller roots. 

 The residual effects of the gas were greater for the continuous than 

 the intermittent treatments. The roots of the plants where the 

 24-hour treatments of carbon dioxide has been given were more 

 affected under the manure than the fertilizer treatments. 



