Miscellaneous. 



538 



[December, 1910. 



partial, as in the cases of many double 

 flowers. The first suggestion of doubling 

 is often only a single additional petal. 

 In the progeny of this individual some 

 with more petals nearly always occur, 

 and the process eventually results in full 

 doubling. The general progress in these 

 cases is seemingly parallel to what occurs 

 in securing the pure lines out of a 

 complex hybrid. A similar case if true 

 is found in Burbank's red Eschscholtzia, 

 the first hint of which was a red streak 

 in the petals of a yellow sort. By con- 

 tinued selection the pure red was 

 isolated. Professor Setchell tells me, 

 however, that red-flowered eschscholt- 

 zias occur wild in certain localities in 

 California. There is room for much dis- 

 cussion on all these points, but their 

 settlement requires a larger body of 

 critical facts than are yet available. 

 There are plenty of gardeners' accounts 

 of such phenomena to be had, and they 

 are probably true, but they do not 

 possess scientific accuracy. Along these 

 lines there is presented an alluring field 

 of botanical work. 



A clearer understanding of the dif- 

 ferent types of degrees of variation 

 is most important. De Vries would 

 recognise only three types, namely, 

 fluctuations, mutations, and ever-sport- 

 ing plants. The latter include mostly 

 plants with variegated leaves or flowers, 

 which also constantly bear part of 

 their leaves or flowers without variega- 

 tion. A common example is the variegat- 

 ed-flowerd larkspur. The azaleas with 

 flowers on some branches red, on others 

 white or striped, offer perhaps a similar 

 phenomenon. 



It is quite certain that such a clas- 

 sification simplifies the matter too much. 

 Johannseu's work with beans clearly 

 shows that mutations are often very 

 small, even minute, but they are in- 

 herited, while similar variations not 

 inherited are considered fluctuations. 



De Vries's complication of available 

 evidence on the origin of plant sports 

 tends to uphold in general the idea of 

 the gardeners, namely, that sports are 

 comparatively rare ; that unusual con- 

 ditions, especially of nutrition, favour 

 their occurrence ; and that often a plant 

 must be cultivated a long time before it 

 will sport. His evidence further shows 

 that in some cases breeders sought out 

 natural sports, and merely intensified 

 their characteristics by cultivation. 

 Whether De Vries's theories are correct 

 or not, wholly or partly, is of far less 

 importance to agriculture than the 

 stimulus he has given to the experi- 

 mental study of plant variation. Not 

 only has he done a vast amount of this 



sort of work himself, but he points out 

 very clearly numerous problems awaiting 



the investigator, 



It is remarkable that thus far so little 

 has been done in attempting to pro- 

 duce anew the varieties of cultivated 

 plants by beginning with the wild 

 plant and conducting the work under 

 critical scientific conditions. This is 

 perhaps impossible in the face of our 

 most important plants which have been 

 cultivated since prehistoric times, and 

 of whose original form we are in many 

 cases ignorant, but it surely is a feasible 

 and logical method of procedure in the 

 case of plants domesticated in recent 

 times, as is the case with many orna- 

 mentals. There is, I believe, no dissent 

 from the statement that cultivated 

 plants show far greater diversity than 

 their wild progenitors. Is this greater 

 diversity merely due to intensification of 

 differences already possible of discern- 

 ment in the wild plant, or do really new 

 types appear under the stimuli of culti- 

 vation? To use a simple example, 

 Impatiens sultani an African orna- 

 mental was first introduced into culti- 

 vation about 20 years ago, only a single 

 colour then being known. It now occurs 

 in four distinct colours. Have these 

 arisen under cultivation, or were they 

 found as wild sports ? A more complex 

 case. Phlox drummondii is a native to 

 Texas and very variable, so far as 

 known only pink, purple and red varie- 

 ties existing wild. It was introduced 

 into cultivation about 75 years ago. 

 There is now a bewildering array of 

 colour varieties, both with entire and 

 with fringed petals. In the so-called 

 star of Quedliuburg varieties the central 

 tooth of the fringed varieties is pro- 

 longed into a lobe as long or longer than 

 the petal. In the wild form there is 

 apparently no hint of such a character. 

 It ought to be no difficult task to repeat 

 the evolution of these forms under test 

 conditions and thus get a full record of 

 what takes place. Until this is done 

 our picture of the process must remain 

 incomplete. How far extreme condi- 

 tions as to soil, heat, moisture and 

 other external factors may affect the 

 process of variation, especially per- 

 manent variations, is one of great 

 interest and importance. Our wide 

 range of soils and climates gives us un- 

 usual opportunity to plan such investi- 

 gations. To start anew with the wild 

 forms of our most important crops, 

 wheat, oats, corn, beans, potatoes, etc., 

 is rendered difficult owing to our ignor- 

 ance of the wild progenitors of these 

 crops. Why these should have disap- 

 peared if such is the case is very puzz- 



