EXERCISE 106 



GERMINATION OF POLLEN GRAIN 

 Materials. Sweet-pea flowers ; cane-sugar sirup. 



Directions for work. Mount pollen on a slide in cane-sugar 

 sirup and cover with a cover glass. To avoid crushing the 

 pollen grains place small pieces of broken cover glass under 

 the edges of the cover. Set aside in a covered dish containing 

 a sponge saturated with water in order to prevent evaporation. 

 Examine from time to time. 



The sugar sirup should be made by dissolving cane sugar in 

 water. Sweet-pea pollen will commonly grow in sirup with a 

 concentration of from 10 to 15 per cent. It is advisable to pre- 

 pare a series of slides with sirups of differing strengths in order 

 to be sure that some of them will show germination. 



References 



BRRGEN and CALDWELL. Practical Botany, pp. 115-117, 325-326. 

 BERGEN and CALDWELL. Introduction to Botany, pp. 134-136, 300-302- 



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