14 



Dansk Botanisk Arkiv, Bd. 2 Nr. 10. 



A 



B 



Fig. 4. 



A. A pollen-mass which has germinated in pendant 

 drop of a 5 per cent cane-sugar solution. X 25. 



B. The germination when 5 pollen-masses have been 

 placed in a pendant drop of a 5 per cent cane-sugar 



solution. X 25. 



Further particulars about the conditions of the pollen-mass 



in culture will be arrived at by cultivating the pollen-masses in 



very small quantities of liquid e. g. in pendant drops. In this way 



the pollen-mass may alter the liquid, but this is evidently an altera- 

 tion, which is of 

 vital import for the 

 development of the 

 tube of pollen. 



It will be found 

 that experiments of 

 culture in pendant 

 drops give constant 

 results. By varying 

 the size of the drop 

 and the number of 

 pollen-masses pla- 

 ced in it the fol- 

 lowing law may 

 be derived: at low 



concentrations (5—10 per cent) it takes less liquid in proportion 



to the pollen-mass to produce a good germination than at higher 



concentrations (20—60 per cent). While 



one pollen-mass in a big pendant drop 



of a 5 per cent cane-sugar solution does 



not germinate otherwise than in a greater 



quantity of liquid of the same concentra- 

 tion, the germination gets the better, the 



more pollen-masses are placed in such a 



drop (vid. Fig. 4). At higher concentra- 

 tions in pendant drop, the quantity of 



liquid may be greater in proportion to 



the size of the pollen-mass than at 5 per 



cent, to produce a good germination, and 



I found that when the proportion between 



the cubic contents of the liquid and the 



pollen-mass was of a certain quantity, the 



germination became far better than I had 



ever found it in greater quantities of liquid, 



and the type of germination resembled the 



one produced in the style, (vid. Fig. 5). 



Upon this I tried how one pollen-mass germinates in greater 



quantities of liquid of different cane-sugar concentrations. Thus it 



Fig. 5. 

 Pollen-mass which has 

 germinated in pendant 

 drop of a 30 per cent 

 cane-sugar solution. X 25. 



