-g THE PLANT WORLD 



seed-pan seems so attractive to the fingers of the thoughtless. 

 The soil looks so smooth and moist that everybody wants to 

 feel just how soft and how moist it is, never dreaming that 

 every time an unguarded finger passes from one seed-pan to 

 another, a fatal question-mark is put into a pedigree that may 

 have cost several years of patient care, and which may have 

 within it the power to solve some problem of far-reaching 

 scientific importance. At one time I discarded six pedigree 

 seed-pans, because earth was thoughtlessly shaken from the 

 roots of lettuce-plants growing in a box of unsterilized soil 

 near the pedigree cultures, by one who did not at the moment 

 see the importance of being careful. To satisfy myself that 

 there was cause for discarding these pans, one of them was 

 saved and in a few days several native weeds were found 

 germinating. As the pedigree-culture was itself that of a 

 native weed, no plant in the pan could be with certainty held 

 to belong to the pedigree indicated by the label. This episode 

 led to the apparently selfish precaution of keeping the pedi 

 gree-cultures under lock and key, admitting no one except 

 when a responsible guide was at hand to guard the seed-pans 

 from thoughtlessness and ignorance; and I would advise 

 the same precaution on the part of every pedigree-culturist 

 who wants to be sure of his pedigrees. 



Two other instances of error of similar catastrophic 

 type have occurred, which may prove of interest. My head- 

 gardener and I were greatly surprised at one time to find 

 violet seedlings coming up in a number of Bursa seed-pans 

 and we were at first nonplussed as to their origin until it was 

 observed that the majority of these grew along the farther 

 edges of the pans, thus indicating that they had come from 

 the direction of the walk. Following this clew it was found 

 that a few violets were fruiting in pots under an adjoining 

 bench. Though these fruiting specimens were three feet 

 below the level of the seed-pans and four feet or more to 

 the side, the force with which the capsules dehisced was suf- 

 ficient to lodge a considerable number of the seeds in the 



