184 THE PI.ANT WORI^D 



greater than would seem, if we knew the length of life of the flower. 

 Edward Bell * takes issue with Weiss, and, admitting his premises, 

 believes that cross-pollination through insect visitation the exception. 

 Bell's observations, coupled with evidence from other sources, seem to 

 strengthen the validity of the exception he takes. We need not here 

 enter into the details of the discussion, since we wish more particularly 

 to point out that, although this plant has been studied again and again, 

 we can not yet point to any satisfactory conclusion. We have still to 

 determine quantitatively whether close-pollination preponderates over 

 cross-pollination, or the reverse, and whether either one of these methods 

 has a value to the plant over the other in the struggle for existence. It 

 is at this point, therefore, that we stand. To put the matter in a general 

 light, we may ask these questions about any particular plant. The field 

 for observation and experiment in this direction is by no means closed, 

 but rather we are just at the beginning. If any one wishes to catch the 

 spirit of scientific inquiry, and to put himself in a position to understand 

 the tendencies of modern botanical thought, he can do this by selecting 

 a plant and making the study of it a constant task till results are yielded. 

 I have suggested in a previous issue that our Houstonia, or Bluets, offers 

 a most excellent material for such study. It is heterostyled, grows 

 readily and rapidly, and is abundant in its area. It is small enough so 

 that a cage or net could be placed over a plant or clump so as to prevent 

 the access of insects. Increasing experience will indicate the precautions 

 to be taken. Close- and cross-pollinations may be made by hand, and 

 the conditions of seed formation controlled in this regard. The growth 

 of plants from these seeds may be followed, and re-pollinations may be 

 made on these plants. 



Finally, it may be added that persistent individual effort in observation 

 and experiment is bound to succeed. It is only necessary to have clearly 

 in mind the goal at which the effort is to be directed, and to carefully 

 exclude error from all operations. If any one is hereby stimulated to 

 undertake such work, the instructive little book by Professor ly, H. 

 Bailey, entitled " Plant Breeding," will be sufficient to orient him. 



THE ORIGIN OF BOG PLANTS. 



A PERUSAi, of Scharff's history of the European fauna, which by the 

 way no teacher of biology can afford to do without, serves to sharpen the 

 appetite for every work which bears on the origin of organisms, whether 

 animal or plant, of any country. Scharff traces the routes by which the 

 denizens of the British Isles came hither and he establishes their ancient 

 homes. This awakens in one the wish that similar work might be done 



♦"The Pollination of the Primrose," Nature Notes, 15 : 63, April, 1904. 



