880 Report oF THE HORTICULTURAL DEPARTMENT OF THER 
When preparation of these cultures was finished, at.5 p. m., 
June 28, they were put into moist chambers and kept in a room 
having nearly constant temperature of about 70° to 72° F. 
When they were examined at 8.40 a. m., June 29, no pollen had 
germinated in any of them except in No. 22 which contained 
2 per ct. sugar solution in water only. In this culture out of 
107 pollen grains 9, or about 8 per ct., had germinated. 
The cultures were kept four days, till July 2, and then dis- 
carded. During this time they were kept in the room above 
mentioned except that on one day, June 29, they were for about 
ten hours in a room where the temperature ranged from 80° F. 
to 82° F. On July 2 the following notes were made: 
No. 15 shows no germination. 
WIND. WO | eueCO. 
No. 17 _ ditto. 
No. 18. ditto. 
No. 19. Twelve pollen grains, or 28 per ct., show evidence of 
germination. In these cases the germ tube has only attained 
a length of from one-half to two-thirds the diameter of the pol- 
len grain and then disintegration has followed. 
No. 20 shows no germination. 
No. 21 destroyed by accident. 
No. 22 shows 52 germinations or 49 per ct. 
About 11.30 a. m., June 19, the following cultures were made 
with rose pollen. 
Series IV. 
Culture Number of pollen 
No. Medium, grains in culture, 
30 Mixture C, 1 part; aqueous solution of cane sugar, 
OD Parts iis. 6Shib whee pizee'p/é epee Ne od mle vated About 150 
81 Cane sugar, 2 parts; water, 98 parts. ........ cece About 150 
These cultures were kept in moist chambers in the laboratory 
till 5.30 p. m., or 6 hours. There were then no germinations in 
No. 30, but 36 pollen grains out of about 15Q@ in culture No. 31 _— 
had already germinated. The cultures were then kept in the 

