New York AGRICULTURAL EXPDPRIMENT STATION. 383 
In culture 10 which contained but 50 parts of the spray mixture 
in 10,000, no more than one-quarter of the pollen germinated, and 
that made even less vigorous. growth than was made in culture 
9. 
In cultare 11 which contained but 2 parts of the spray mixture 
in 10,000, and in culture 12 which contained but 1 part in 10,000, 
the germination of the pollen and growth of pollen tubes 
progressed freely. 
Series II.—Culture media contained cane sugar solution in water — 
and Bordeaux mixture.—In the 2 per ct. aqueous solution of cane 
sugar alone the pollen from Ben Davis apple germinated freely 
and the growth was vigorous and abundant. When 200 parts 
in 10,000 of ordinary Bordeaux mixture were combined with this 
sugar solution, culture 8, germination was almost wholly stopped. 
But two pollen tubes started to grow and one of these soon 
became disintegrated. When 500 parts Bordeaux mixture in 
10,000 were used with a stronger (5 per ct.) sugar solution in 
water ho germination took place. 
Series III —Culture media contained cane sugar solution in water 
combined with Bordeaux mixture made from chemically pure 
ingredients ; also with lime alone and with lime and green arsenite 
of copper.—in this series blackberry pollen was used. Even in 
the dilute sugar solution alone hardly half of the pollen grew. 
Bordeaux mixture of the strength commonly used in spraying 
orchards, mixture C, was used at full strength and also was 
diluted with the weak sugar solution till it formed in the different 
cultures respectfully 200 parts, 100 parts, 50 parts and 2 parts 
in 10,000. In none of these media except the last named did 
germination take place, in which case 28 per ct. of the pollen 
grains in the culture started to germinate but before further 
growth took place disintegration followed. It appears that the 
| blackberry pollen is even more sensitive to the poisons commonly 
used in making spray mixtures than is apple pollen. The copper 
arsenite and lime when not combined with Bordeaux mixture 
prevented germination of the pollen. Even the lime alone seemed 
