8 LOUISE DOSDALL 



In some cases these spring plants grew. almost to the full size 

 attained in the field. 



During the latter part of October some Equisetum hyemale 

 was found growing in the glen along the Mississippi river at 

 Fort Snelling, Minnesota. These plants were growing on the 

 side of a hill in deep shade. The root systems proved to be 

 rather shallow and when the plants were transferred to the 

 greenhouse only a few of the stems turned yellow. Throughout 

 the winter abundant new shoots developed while most of the 

 old stems died down towards January. Equisetum arvense was 

 dug early in April. Ranunculus sceleratus was grown from seed- 

 lings, which Mr. Folsom of the Botanical Department of the 

 University had grown in mud for a number of generations. The 

 plants of Bryophyllum calycinum were cuttings from plants 

 which had grown in the greenhouse for a number of years. 

 Helianthus annuus and Phaseolus vulgaris were grown from seeds. 



(2) WATER CONTENT METHODS 



In determining the wilting coefficient of Equisetum fluviatile, 

 and Ranunculus sceleratus essentially the same wax-seal method 

 recommended by Briggs and Shantz (1912: 10) for the direct 

 determination of the wilting point was used. The plants, how- 

 ever, were grown approximately six weeks in soil sifted through 

 a two millimeter screen before being sealed for wilting. The 

 exact time elapsing before the seal was applied differed with the 

 season because the plants started in spring grew much more 

 rapidly than those started in fall. Through an inadvertence 

 Equisetum hyemale growing in sandy loam was used for the 

 wilting coefficient and consequently a direct comparison with 

 the others cannot be made. 



In most cases Equisetum wilts very suddenly, the collapse of 

 the upper part of the plant indicating that the critical point in 

 the absorption of water has been reached. Very similar wilting 

 effects result from other causes. If the wax is too warmwhen 

 put around the stem the latter is injured and the whole plant 

 collapses. This can be distinguished from true wilting by the 



