BIOTYPES AND HYBRIDS. 



A VARIABLE SERIES OF DOUBTFUL SIGNIFICANCE. 



27 



Besides the four forms named and described above, which have been 

 shown to breed true to type with only sHg-ht fluctuations, most of my at- 

 tention has been given to a series of cultures whose behavior has been up 

 to the present time quite baffling". Some time I hope to understand this 

 g-roup better, and I shall then have more to say about it, but its behavior is in 

 such striking contrast to that of the biotypes already described that it 

 seems only fair to give a short epitome of my results as they now appear. 



Fig. 18. — Bursa bur sa-pastorisrhomboidea grown from guarded seed 

 of the plant shown in fig. 17. 



Two specimens (040.2 and 040.7) were taken into the sky-lighted room 

 from different habitats near Cold Spring Harbor, Long Island, in the very 

 beginning of these cultures, April 15 to 20, 1905, and allowed to ripen seed. 

 The aspect of these two specimens was very diverse. One (040.2) was 

 robust and had rather firm, thickish leaves with 4 or 5 pairs of oblong, ob- 

 tuse, wavy lobes, while the other (040.7) had a small rosette with thin, 

 flat leaves and few triangular lobes. Notwithstanding these differences, 

 the offspring of the two plants, as followed in numerous cultures through 

 several successive g-enerations, were indistingtiishable from each other. 



