3i8 PLANT HYBRIDIZATION BEFORE MENDEL 



"For the characters of form of pod, color of pod, and position of 

 flowers, experiments were also made on a small scale, and results ob- 

 tained in perfect agreement. All the differentiating characters duly ap- 

 peared, and in nearly equal numbers." (p. 361.) 



It is therefore evident that Mendel was justified in arriving at 

 the conclusions : 



"Experimentally, therefore, the theory is confirmed, that the pea hy- 

 brids form egg and pollen cells which, in their constitution, represent 

 in equal numbers all constant forms which result from the combination 

 of the characters united in fertilization." (p. 361.) 



"The law of combination of different characters which governs the 

 development of the hybrids finds therefore its foundation and explana- 

 tion in the principle enunciated, that the hybrids produce egg cells and 

 pollen cells which in equal numbers represent all constant forms which 

 result from the combination of the characters brought together in fer- 

 tilization." (p. 364.) 



Mendel finally concludes this memorable paper with a brief 

 account of crossing experiments with a Pole Garden Bean, Phase- 

 olus vulgaris, growing 10 to 12 feet in height, and Phaseolus 

 nanus, a dwarf variety. Phaseolus vulgaris had yellow pods con- 

 stricted when ripe, and Phaseolus nanus green pods inflated when 

 ripe. Mendel found that tall stems, green pod-color, and inflated 

 pod-form were dominant over short stems, yellow color, and con- 

 stricted pod-form. 



This concludes a rather full account and analysis of Mendel's 

 celebrated report on the behavior of hybrids. Nothing in any 

 wise approaching this masterpiece of investigation had ever ap- 

 peared in the field of hybridization. For far-reaching and search- 

 ing analysis, for clear thinking-out of the fundamental principles 

 involved, and for deliberate, painstaking, and accurate follow- 

 ing-up of elaborate details, no single piece of investigation in this 

 field before his time will at all compare with it, especially when 

 we consider the absolute absence of precedent and initiative for 

 the work. In a way, Darwin's experimental work in the crossing 

 of plants resembles it. Indeed, when we regard Mendel's work in 

 the light of its pioneer quality, exhaustive mastery of details, 

 marshalled throughout with reference to a fundamental motive 

 that was never lost sight of, we may well find no comparison for 

 Mendel's work than with that of Darwin. 



