THE EASTERN HEMLOCK. 19 



The cones are extremely sensitive to moisture, a small amount of 

 water causing the scales to close rapidly. When thoroughly wet 

 the scales of a cone become completely closed, in some cases within 

 10 minutes and in most cases within 20 minutes. Even a damp 

 atmosphere, without the actual contact of water, will cause the cones 

 to close to some extent. 



The advantage to the species of this property of the cone is appar- 

 ent. The cones when mature expand their scales so as to permit 

 the seeds to escape, but as the latter are attached to a membra- 

 nous wing which adheres to or rather forms a part of the inner face 

 of the scale, they do not easily fall out. A passing shower or a rain 

 causes the scales to close, again to open as the air becomes dry. 

 This process continues for many months, with the effect of loosening 

 the seeds successively from autumn until spring, and thus a bearing 

 tree makes a succession of sowings extending over a considerable 

 length of time. As a result the wind, blowing during this period 

 from different points, carries the seed now in this direction and now 

 in that, and thus a fruiting tree stands in the center of a considerable 

 area which it has sowed with seed. 



The seed (see/ and g, fig. 3) is about one-sixteenth of an inch long 

 and about two-thirds as broad. The attached wing, an exceedingly 

 delicate and almost transparent membrane, extends about a fourth of 

 an inch beyond the end of the seed, and is an eighth of an inch broad 

 at its widest point. On the under side, next to the cone scale, are a 

 number of minute glands or vesicles, usually from 4 to 8, each con- 

 taining a minute drop of oil. The seed of the Carolina hemlock has 

 15 or 20 vesicles, which are much smaller in size than those of the 

 common species. 



According to Forest Service determinations, there are about 

 400,000 clean seed (without wings) per pound. The seeds weigh 

 1.13 grams (0.04 ounce) per 1,000, and the germination per cent is 

 from 30 to 60. 



MANNER OF GROWTH. 



In the climate of central New York the growth of a vigorous tree 

 usually begins during the first half of May. The terminal buds are 

 the first to open, and in about two weeks develop into shoots a half 

 inch long, thickly set with the half -grown, yellowish-green leaves. 

 The dark-green twigs and branches appear as though fringed with 

 gold; and it is now that the hemlock tree takes on its most striking 

 and peculiar beauty. The shoot continues its growth during the 

 season, being constantly tipped with a rosette of small, forming 

 leaves, while those previously formed are scattered on the constantly 

 growing stem. 



