38 BURS A BURSA-PASTORIS AND BURS A HEEGERI : 



of the best examples of B. dp. heteris. The seeds were sown March 6, 1906, 

 and produced a uniform progeny of B. dp. heteris, some fluctuation being- 

 noted in the denticulation of the primary lobe. None of these were potted, 

 but 103 specimens were cut from the seed-pan, all being- of the same type 

 as the parent. 



054.21: This was a specimen of B. bp. rhomboidea. The seeds were 

 sown March 6, 1906. The plants were allowed to become too crowded in 

 the seed-pan, and did not reach their best development. Their g-eneral 

 aspect was homogeneous, but examination of the lobes showed some similar 

 to B. bp. simplex, others more like B. bp. rhomboidea. The status of the 

 simplex-\&& specimens in this progeny is not known, but it seems probable 

 that many of them were really B. bp. rhomboidea, in which the characteristic 

 incisions failed to develop because of the crowding of the plants. 



054.25: This plant was a well-developed specimen of B. bp. tennis, with 

 occasional secondary spurs on the proximal margin of the primary lobes, 

 but with no trace of a rounded secondary lobe in the distal axils. The 

 seeds were sown April 18, 1906, and produced 136 young plants. When 

 examined in August, after my return from 2 months' absence in California, 

 54 were dead. The rest were all B. bp. tennis, or modifications of it, except 

 3 which were B. bp. heteris. Unless the latter were the result of chance 

 crosses their origin is not understood. 



054.26: This specimen belonged to the most distinct type of B. bp. heteris. 

 The seeds were sown April 18, 1906, and produced 173 offspring. About 

 20 died and the remainder belonged to B. bp. heteris, and B. bp. tennis in 

 the ratio 119 : 34 or 3.5 : 1. Some of the specimens classed as B. bp. heteris 

 had the primary lobe rather strongly incised on both margins. This is 

 a character frequently seen in robust specimens of B. bp. tenuis, and it is 

 possible that this represents a slight lack of complete dominance of B. bp. 

 heteris over B. bp. tenuis. 



054.27: This plant had large, wide-spreading, rather thickish, stiff, 

 strongly bipinnatifid leaves, with all the lobes tapering and acute, agreeing 

 thus, in an essential way, with the parent (040.4). The seeds were sown 

 April 18, 1906, and produced about 270 offspring. These are seen now to 

 indicate that the parent was a di-hybrid, but at the time the family was being 

 studied the distinctness and the limitations of the several forms were not 

 sufficiently appreciated, and the notes made at that time were in the terms of 

 a dominant and a recessive group, the dominant group having the sinuses 

 extending to the rachis and the terminal lobe more evenly rounded and 

 more cuneate than in the recessive group, which had the sinuses much less 

 deep. If these distinctions were consistently made throughout, the result 

 should be the same as that of a simple Mendelian hybrid, since the former 



