384 Report oF THE HorTICULTURAL DEPARTMENT OF THB 
to have the same effect, but only one incomplete test was made 
with this material in this series. 
See also Series V. 
Series IV.—Bordeaux mixture made as in Series III compared 
with an aqueous solution of sugar cane alone-—Bordeaux mixture 
made as for Series III and diluted to 100 parts in 10,000 of the 
2 per ct. aqueous sugar solution wholly prevented the germina- 
tion of rose pollen in culture 30 while in the corresponding 
culture containing the sugar solution alone there were many 
germinations. 
Series V.—Culture media as in Series ITT.—The media used in 
Series ITI when tested on pollen of Virginia creeper, Ampelopsis 
quinquefolia, showed a like effect in kind only to a slightly less 
degree than with the blackberry pollen. In the cane sugar solu- 
tion in water alone 75 per ct. of the pollen germinated; in the 
aquenus solution of cane sugar with 2 parts in 10,000 of the 
Bordeaux mixture C added, 67 per ct. germinated; with 50 parts 
in 10,000 added, 4 per ct. germinated; with 100 parts and with 
200 parts in 10,000 added there was no germination. The copper 
arsenite and lime in culture 37 prevented germination as did also 
lime alone in culture 36. 
Series VI.—Culture media of this Series duplicate those used in 
Series III except culture 21.—Pollen of Japan ivy Ampelopsis 
tricuspidata, tested in the media used in Series III and V showed 
76 per ct. germination in the cane sugar solution alone; 93 per ct.t 
in thé medium containing two parts of Bordeaux mixture’ © in 
10,000; no germination took place in the media containing respec- 
tively 50 parts, 100 parts and 200 parts of the Bordeaux mixture 
C in 10,000. In the medium containing copper arsenite and lime 
there was no germination. 
From these investigations it appears that if before pollination 
occurs the stigmatic surface of the pistil should be covered either 
*This culture contained but 15 pollen grains while the cane sugar solu- 
tion just mentioned contained 119 pollen grains. Judging from general — 
experience with these cultures it seems quite probable that had the former 
culture contained an equal number of pollen grains the percentage of 
germination would have been no higher than it was in the latter culture. 
