56 BOTANICAL GAZETTE [JANUARY 
the maximum, optimum, and minimum temperatures for chloro- 
phyll formation in the seedlings being represented by temperatures 
somewhat below 30, 15, and somewhat above o° C. 
Seedlings grown at o+ 1° C. developed anthocyanin, while those 
grown at 30° C. developed xanthophyll. When cultures at o= 1° C. 
were supplied with glucose they developed more anthocyanin. 
The seedlings grown at 30° C. were made to develop anthocyanin 
by the addition of glucose. From the foregoing it appears that 
the seedlings form various pigments according to their reserve sugar 
TABLE XXII 
EFFECT OF LIGHT AND TEMPERATURE ON DEVELOPMENT OF CHLOROPHYLL* 
E OF COLOR AFTER TRANSFER 
TEMPERATURE Licat 
1 day | 4 days | 6 days | 8 days | 11 days| 13 days | 18 days | 26 days! so days 
a. Light ° ° ° ° ) ° ° | ) 
2 5. Co Light S 25 50 50 50 Oe eas alone as 
15. Cs. Light 5 25 50 75 7 $60 bu os oie he sang 
10° Or aan Light 5 25 50 via a eed cree TOO: [a fees ae 
10° Cy Dark 5 25 50 fies Sea a ech ee a 400. [os55 eles 
= Co bs as ea Ges ae Par hee ee ae SON tees ae 
sit oe BB ae, ee Ce en A AE as Ce en BO tle ee kawe ses 
cade te PERG ee BAM tl owls bed aa ti ewae bee skhic avi oves eet ° 
omnes... Dark ea ea ee | ipmte thease ea Nea ° 
*Average of 50 trials. 
supply. Seedlings with little sugar tend to develop xanthophyll, 
those with more sugar chlorophyll, and those with an abundance 
of sugar anthocyanin. 
PRACTICAL APPLICATION.—The foregoing experiments make it 
possible to devise an outline for the practical production of juniper 
plants. This should be of interest to growers, since it has furnished 
a means of increasing many fold the percentage of germination and 
of developed seedlings. After collection, the seeds are freed from 
the berries, sorted, and sterilized as has been described. The seeds 
are then put into Petri dishes or covered flat vessels on filter paper 
supported by wet cotton. These vessels of seeds are kept at a 
constant temperature of about 5° C. (41° F.) for after-ripening, 
which takes about too days. This after-ripening period can be 
shortened ro days by drying slightly and moistening again the 
seeds at about the forty-fifth day. When the coats have split 
