48 THE AMERICAN BOTANIST 



foot violet besides other unrecognized weeds. Certainly plants 

 can grow and thrive under conditions that would be thought 

 anything but ideal in a flower gar'den. From what we know 

 of selective absorption by plants it seems likely that a variety 

 of plants have a better chance of growing in close proximity 

 than a pure stand of a single species. Possibly we could plant 

 our flower gardens in this way with good results. 



Vitality of Pine Seeds. — It is well known that various 

 species of pine in the Western United States retain their cones 

 arid seeds for a number of years after the seeds are mature. 

 Sometimes these cones remain on the tree for nearly twenty 

 years. The question having arisen as to the vitality of the 

 seeds in such aged cones, several experiments have been made 

 in order to settle the matter. T. C. Blumer experimented with 

 six thousand seeds and found the older seeds not only as viable 

 as the younger ones but more so. Out of three thousand from 

 ten to thirty years old, 40% retained their vitality, while of a 

 similar number of seeds les than ten years old, only 31% grew. 

 The advantage of this prolonged vitality is that it gives the 

 trees a distribution in time similar to the distribution in space 

 of other trees. A forest of such pines may thus be repro- 

 duced in a locality more than thirty years after the last living- 

 specimens have disappeared. 



Plant Hairs and Nitrogen. — We have many theories 

 and some facts to account for the uses of plant hairs but no- 

 body is sure that we have arrived at a correct solution of the 

 problem. Plant hairs may prevent the clogging of stomata 

 by rain or dew, or they may absorb water on occasion ; 

 they may protect from evaporation by shading the leaves, they 

 may afford a partial defence against sudden changes of tem- 

 perature and they may protect in a measure from the attacks 



