﻿BOTANICAL GAZETTE 



formed pollen tubes 617.9 M l° n g; ( c ) many had germinated, but 

 the pollen tubes were short, being 133 . 6 ix or less in length. 



SERIES 11 



June 12, 1 91 3. — Pollen grains which were collected on May 27 

 and were started at 3 : 50 p.m. in the laboratory, the temperature 

 being 15 0 C. As in all other experiments, they had been kept dry 

 since the date of collecting. Three cultures were made, namely, 

 (a) 4, (b) 8, and (c) 16 per cent sugar solution. They were exam- 

 ined at 4:20 p.m. on June 13, the temperature being 15 0 C. The 

 results were as follows: (a) many had germinated, some of the 

 pollen tubes being 601.2 n long; (b) many had germinated, the 

 growth being better than in (a); some of the pollen tubes were 

 701 .4 \i long; (c) many had germinated, some of the pollen tubes 

 being 551 . 1 y. long. 



SERIES III 



August 6, 1913. — The cultures were started at 5:00 p.m., the 

 temperature in the laboratory being 16 0 C. The pollen grains 

 had been collected on May 27, 1913. They were in 4 per cent 

 sugar solution and were examined at 4:45 p.m. on August 7, the 

 temperature being 16 0 C, but none had germinated. On exam- 

 ination at 5:00 p.m. on August 8, the temperature being 16 0 C, it 

 was found that a few short pollen tubes had been formed. 



Strawberry 



SERIES I 



An open flower was plucked on May 27, 1913, the weather 

 having been dry for several days. The flower was kept dry until 

 May 29, but still the anthers did not open. On teasing the anther 

 on a slide no pollen grains escaped, but when the anther was 

 teased in water small pollen grains were found which were sub- 

 globular in shape, but more or less shriveled and about 18 m in 

 diameter. Cultures in 4, 8, and 16 per cent sugar solution were 

 started at 11 .'05 a.m. on May 29 in an incubator at 21 0 C, but at 

 4:40 p.m. none had germinated. 



