﻿1.34 



BOTANICAL GAZETTE 



germinated and the growth was much less than in (a) ; consider- 

 able evaporation had taken place; (c) a considerable number had 

 germinated but the growth was less than in (a) ; some evaporation 

 had taken place; (</) some had germinated and formed fairly long 

 tubes; some evaporation had taken place; (e) sl very few had 

 formed short pollen tubes; very little evaporation; (/) same as 

 (e); (g) only one pollen tube observed; evaporation very slight; 

 (h) none had germinated; evaporation very slight. 



A 2 . — Inside cultures: 10:15 A - M -> Ma Y 8 5 temperature 15° C: 

 (a) some had produced very long tubes and appeared to have 

 almost exhausted the reserves in the pollen grain; there were a few 

 which did not germinate; (b) same as (a); (c) pollen tubes mostly 

 short; a very considerable number had not germinated at all; 

 (d) these had formed much longer pollen tubes than in (c); the 

 pollen grains were larger than those in (c) and may have been 

 obtained from a different variety; some did not germinate; (e) 

 same as (d) ; (J) many had formed comparatively long pollen tubes, 

 although a considerable percentage did not germinate; (g) a num- 

 ber had formed pollen tubes of variable length, although the 

 majority did not germinate; (h) three were observed with short 

 pollen tubes. 



B 2 . — Outside cultures: 11:00 a.m., May 8; temperature o° C; 

 temperature at 3:00 p.m., when they were examined, was n° C: 

 (a), (b), and (c) same as on previous day; (d) a considerable 

 number had formed short pollen tubes, but many had not germi- 

 nated; (e) and (/) same as on previous day; (g) an extremely small 

 number had formed short pollen tubes; (h) none of the pollen grains 

 had germinated and very few of them had swelled. 



A 3 . — Inside cultures: 3:35 p.m., May 9; temperature 18 0 C: 

 (a) same as on previous day; (b) a considerable number had not 

 yet germinated; (c), (d), (e), (/), and (g) same as on previous day; 

 (h) a considerable number had formed fairly long pollen tubes. 



B 3 . — Outside cultures: 3:55 p.m., May 9; temperature 12 0 C: 

 (a), (b), and (c) same as on previous day; (d) a considerable num- 

 ber had formed pollen tubes of moderate length; (e), (/), (g), and 

 (h), same as on previous day. 



In all cases the pollen grains appeared to have 3 germ pores. 



