438 THE AMERICAN NATURALIST [Vol. LV 



made. Eacli slide was so prepared tliat about 100 pollen 

 grains would be visible in a single field of the microscope. 

 All the grains in the field were then counted and the 

 percentage of sterile grains calculated and averaged. 

 Only two plants showed more than 3i- per cent, of sterile 

 pollen. One normal dark blue plant showed 40 per cent., 

 39 per cent, and per cent, in three flowers. One striped 

 white showed 9 per cent., 6 per cent, and per cent, in 

 three counts. One hybrid light blue, one dark blue and 

 one pink showed no iiifci tilc polhMi. The one plant with 

 a high degree of sterility was a selt'od dark blue apricus. 

 Only a few plants of uco/us were available, but they 

 showed no poorer pollen than apricus and pipersmithii. 



Seed Germination.— In a previous paragraph it has 

 been pointed out that, although lupines produce immense 

 quantities of seeds, field germination is apparently poor 

 — at least an abundant seed harvest is likely to be fol- 

 lowed by a poor stand of plants the following season. 

 Our earlier attempts to grow them in the garden were 

 practically a total failure. 



The first attempt to grow controlled cultures was made 

 in the winter and spring of 1914- '15. Four hundred 

 seeds were planted in pots in ordinary unsterilized 

 garden soil and 400 more in pots of sterilized soil (ster- 

 ilized in an Arnold steam sterilizer). The seeds them- 

 selves were planted dry without treatment of any sort. 

 The results were almost a total failure. About 5 per 

 cent, of the seeds produced seedlings. Of these all but 

 5 or 6 were killed as seedlings by the attacks of soil fungi 

 or just simply died. Two plants lived to flower, but failed 

 to set seed. It ap])eared evident that greenhouse cultures 

 under the cotKlitioiis then availal)!*' were likely to be un- 

 profitable and tlic r.niain.lcr ct' tlic ori-iiial seed collec- 

 tions were held over until an cx] x'l'inient garden could be 

 secured. 



In 1917 the remainii?,-'- mv(1< wct-c planted without treat- 

 ment in the open ganlcn. Nine j.Iants in all lived to 

 mature seed — one light blue, one striped white, one pink 



