224 EXPERIMENT STATION RECORD. [Vol.40 



out in the greenhouse at different seasons of the year with potato varieties 

 under different and comparahle conditions of temperature, moisture, and cul- 

 ture, in order to ascertain the effects upon subsequent growth of the plant, it 

 was found that after-ripening occurred either in the ground or in ordinary 

 storage. Potatoes planted immediately after maturation required n much 

 longer time to germinate and appear above ground than did those which had 

 passed through a rest period, and the tubers planted without a rest period pro- 

 duced but one sprout These plants also had a longer growing period than did 

 those from rested tubers, and in the case of plants from Donrested tubers «he 

 seed tubers were usually recovered, havii but little of their original 



weight These tubers when planted the second time germinated und grew 

 sprouts from several buds, the period of growth underground being about 

 equal to that of normal plants and tin Ing period being nearly equa 



that of the first planl 



Regeneration of Bryophyllum calycinum, EL LUCI BBAT7ZI [Bot. Qaz., ('>■'> 

 [1918), No. ft, jip- 191-198, I).- The author clt< - on pot-grown 



specimens of B. calycinum, the conclusions from which are somewhat at vari- 

 ance with th-'se reached by Loeb I E. S. EL, .".T. p, 127). From leaves which had 

 received do special treatmenl Bhoots grew more abundantly from uotches than 



is usually the Cat •' leaves producing .-hoots from all except the basal 



notches. 



Healthy and sick specimens of Bryophyllum calycinum. .1. Lois i Hot. (,'.;;., 

 66 [1918), S o t, | Referring to the statements noted above, the author 



states that the plant observed by Miss BraUD is abnormal, the bend in the stein 

 acting as a partial block and causing BUCh B stem tO behave like an isolated 



piece of stem whose leaves are destined to give risi 



Chemical basis of correlation. — I. Production of equal masses of shoots 

 by equal masses of sister leaves in Bryophyllum calycinum. J. Loxs {Bot, 

 r,a;., 65 [1918), No. .. pp. ISO /?;. fle Having Bhowu in a paper pre- 



viously noted (B. S. EL, 87, p. 127) that when in />'. oalydnum one organ in- 

 hibits the bud growth of anothe^lne inhibited organ contributes in son.. 

 the material for growth in the inhibiting o and having in a prellmln 



Btatemenl (E. S. EL, 37, p. 324) shown that the quantity of material available 

 for shoot formation Is definite and limited, s.. that inhibition may result from 

 retention or utilization of B part thei by the inhibit. in, the author 



gives a somewhat detailed account of work bearing more particularly on the 

 hitter of these points. 



It is stated that in equal time and under like conditions equal masses of 



sister leaves (those arising at the same point) produce approximately equal 



lea- es of shoots, even though the Dumber thereof may vary considerably. The 

 shoots first appearing attract automatically (by a mechanism not yet known) 

 the material available for shoot formation, withholding it from other buds. 



The Inhibiting effect of first-developed buds on other buds Is thus explained by 



the two factors, limitation of available material ami automatic attraction of 

 material to the buds first appearing. A liberal amount of water supplied to a 

 given notch would Insure priority of shOOl formation at that point. 



The law controlling the quantity and rate of regeneration. .T. Loss [Proa 

 Nat. Acad. Set., ', [1918), S <>■ -}. pp. 117-121). Having found that if leaves of 

 Bryophyllum calycinum are isolated from the stem they regenerate shoots in 

 SOme or many of the notches, and that if a piece of the Stem is cut from the 

 plant it will form shoots from its buds nearest the apex, also that the mass of 

 the shoots is directly proportional in the former case to the mass of the isolated 

 leaf and in the latter to that of the attached leaf, the data BUpportlng this state 

 ment having been noted above, the author reviews some of the data formerly 



