THE PLANT WORLD 63 



condition, but wherever they are crowded together the lower ones die. 

 They are unable to receive enough light, and the upper ones do the work 

 for the entire tree. As fast as they die and drop off the scar is covered 

 as we have seen. Failure to do this properly and soon enough results in 

 permanent injury, and the decayed portion spreads down through the 

 trunk, giving in time a hollow. 



Frost-Weeds and Other Winter Notes. 



By Frederick H. Blodgett. 



To THE winter botanist there usually comes a hope, as he starts for 

 his half-frozen swamp, that he may somewhere on his ramble find some 

 one or more of the ' ' Frost-Weeds ' ' with their curious and beautiful 

 crystals. It was the good fortune of the writer some time ago to be one 

 of a small party of these winter ramblers, and to find a considerable group 

 of the Dittany with frost crystals of ice in several forms, some of which 

 were fortunately preserved as sketches, made directly from the speci- 

 mens (see page 64). 



One of the most beautiful of the crystals seen was the one shown in 

 the sketch as Fig. 1. This band of ice issued from the side of the stem 

 at nearly right angles, and extended for a half inch in a nearly straight 

 line. Beyond this point it curved to the left and downward so that the 

 tip was a little lower than the under side of the band of ice as it issued 

 from the stalk. In making this cur\^e the tip formed nearly a complete 

 turn, as is shown in the figure. Along the concave side of the band 

 there appeared a wavy line ; this was formed as a slightly raised portion, 

 and was present on the one side only. In section the band was slightly 

 triangular, as appears in the sketch. 



The second sketch shows a crystal which was almost flat for most of 

 its length, but which formed a hollow, somewhat tubular expansion at 

 the end. This is shown in the sketch, as is also the banding of the whole 

 formation, by parallel lines of less dense ice, giving the appearance of 

 darker material. The formation of the hollow end is a puzzle for which 

 it would be hazardous to risk a guess, so the sketch is left to take care 

 of itself. In the third case several ice crystals emerged from the same 

 stem at nearly the same point and in their development assumed curves 

 and irregular outlines to which it is difficult to do justice in a drawing. 

 Figures 3 and 4 show two views of this specimen, one in front, the other 

 in a position as if viewed from the point "a," Fig. 3. 



The day following the snowfall of January 10 showed some interest- 

 ing features in places where there were steep slopes with a few trees or 



