BIOTYPES AND HYBRIDS. 37 



again the result of chance crosses, their appearance here seems at present 

 inexplicable. A small number of specimens in this family were too stunted 

 by unfavorable conditions to render classification possible, and some of 

 these may also have been B. bp. heteris, but it is probable that most of these 

 stunted specimens were B. bp. tenuis. 



054.3 : The lobes of this plant were attenuate and rather distant, the 

 terminal lobe spatulate or obovate, obtusish, dentate. Seeds of this B. bp. 

 tenuis were sown March 3, 1906, and the 18 offspring" observed were doubt- 

 less all B. bp. tenuis, though there was considerable variation in the degree 

 of lobation, the least-lobed being stunted and not greatly different from 

 B. bp. simplex. 



054.4: This was a robust specimen which had the earlier climax-leaves 

 similar to B. bp. heteris and in the later rosette-leaves had long, attenuate, 

 acute lobes, deeply cut on both margins. The seeds of this plant were 

 sown March 3, 1906, and none of the specimens were potted, but 47 were 

 cut from the seed-pan. It was found that classification of Bursa from the 

 seed-pan is very difficult and uncertain in some cases quite impossible 

 owing to crowding and consequent stunting and suppression of characters. 

 The specimens of this family removed from the seed-pan were classified 

 thus: 30 B. bp. heteris, 6 B. bp. tenuis, 4 B. bp. rhomboidea, and 7 interme- 

 diate between B. bp. heteris, and B. bp. rhomboidea. It is obvious that this 

 was a complex hybrid, and the number of specimens available was too small 

 for the satisfactory working out of ratios. The excessive proportion of 

 B. bp. heteris is easily explainable, because this form has its distinguishing 

 marks less easily rendered latent by bad cultural conditions. 



054.6: This plant had all the lobes simple and mostly obtuse. It should 

 be an extracted recessive, and therefore incapable of producing any other 

 than its own normal characteristics. Seeds were sown March 3, 1906. 

 All of the plants produced seemed to be B. bp. simplex, though only 1 

 was potted. 120 specimens cut from the seed-pan agreed with the char- 

 acters of the parent. 



054.7: The lobes of this plant were rather broadly compound, with all 

 the lobes rounded, agreeing with the characters of B. bp. rhomboidea. The 

 seeds were sown March 3, 1906. None of these were potted, but 43 speci- 

 mens cut from the seed-pan were typical B. bp. rhomboidea; some specimens 

 more nearly resembled B. bp. simplex, but opportunity was wanting to 

 test this point, and a doubt remains whether these were true B. bp. sim- 

 plex, or whether they were specimens of B. bp. rhomboidea in which the 

 characteristic incisions were wanting because of crowding in the seed-pan. 



054.20: The plant to which this number was assigned had the long, 

 clean-cut, primary lobe and well-marked rounded secondary characteristic 



