62 TJic Different Moiirs of Oricjin of new Species. 



cultivated varieties are as old or even older than cultiva- 

 tion itself. 



It we examine a number of such derived forms in any 

 systematic work or llora, it immediately becomes evident 

 that the same kind of dil'ferences recur in the most widely 

 separated families, genera and species. Everywhere \ari- 

 eties present series of parallel forms. The recurrence 

 of white flowered varieties in numerous species with blue 

 or red flowers is so familiar a phenomenon, that often 

 all reference to them is omitted. Lixnaeus himself knew 

 that nearly all such species had a white variety. If the 

 color of a flower is compound, and if one of the compo- 

 nents is lacking, a white flower with a dark center often 

 results and is known as a J\ir. bicolor (for example C\'iio- 

 (/lossimi officinale bicolor, Agrosfeninia coronaria bicolor) : 

 or the dark patches are absent as in Gentiana fnnclafa 

 concolor, which case is exactly analogous to that of Arum 

 niaculatuni inunaculatuin. 



Often too, the clothing of hair is lacking either on 

 the whole plant or, when only certain parts are densely 

 hirsute in the "species," on these. The nomenclature of 

 the series of parallel forms, under this heading, is par- 

 ticularly rich in terms which all indicate the same prop- 

 erty, as for example : Papaver dubiuni (jlabruni, Biscn- 

 tella laez'if/ata glabra, Arabis cilia fa f/labrafa, Arabis hir- 

 siifa glaberrinia, 1/cronica spicafa nifens, Aniygdalus Per- 

 sica lacz'is, Eritrichiuni nanuni leiospernuun, Paconia 

 corallina ( peregrina) leiocarpa, etc. 



Thornless forms are usually termed inerniis; they oc- 

 cur in Raniincnhis ar^'cnsis. Genista gernianica, Robinia 

 Pseud-Acacia and many others. 11ie J\irietas ciliata 

 occurs in Cytisiis prostratus and in C. spinescens, als(^ in 

 Lotus corniculatus, etc. A dense clothing of hair is the 



