— 207 — 



(3) : A dark spot in front of the style: (fig. c). It may be 



either present or absent: 



(nmc), non maculatus: without spot, 



(mac), maculatus: with spot. 



(4) : The pollen-magazine: The middle part of the spur-bearing 



petal is supplied with a great many peculiar hairs, that group 

 themselves in such a way, that they form the wall of a cavity 

 that opens upward and catches the pollen that falls from the 

 stamens. This cavity Wittrock (1897) calls the "pollenmaga- 

 zine." In front it may be shaped in various ways: 



open (ap = apertus): fig. d. 



half-closed (sem = semi-clausus): fig. e. 



closed (ci = clausus): fig. /. 



(5) : The honey-streak upon the spur-bearing petal can be: 



unbranched (nfc = non furcatus): fig. g. 

 branched (fc = furcatus): fig. h. 



(6) : The colour of the petals: Several elements can be present: 



The more frequent of those are: 



Yellowish white (alb = albidus) as in the common 

 V. arvensis. 



Blue (v = violaceus) as in the common V. tricolor. 

 Yellow (lut = luteus): a bright yellow colour. 

 Rose-red (r = roseus). 



As those characters: 



(1) are the same in all flowers from the same plant, and 



(2) are different in different individuals from the same growing 

 place — in the most mixed populations, plants that grow 

 just beside each other differ nearly all in several of those 

 characters — 



they cannot be modifications caused by growing-place but must 

 be of genotypical nature. 



Supposing that in nature those characters combine freely, 

 we should get for the five first 2x2x2x3x2 = 48 

 different combinations = Isoreagents (Raunkiær 1918 p. 

 236) in regard to those five characters. As this division is 

 constructed, any Viola tricolor and arvensis can be placed under 

 one of those 48 possibilities. If the four more common colours also 

 are taken into consideration, we should get 192 possible combina- 

 tions. 



