RANDOM NOTES ON NATURAL HISTORY. 



91 



The dirt froni this cellar was dumped 

 alonji; the rood near by, and for 3'ears after- 

 words, one could i)ick 11 [) beautiful cr^'Stals 

 after a shower had washed the dust from 

 them, so as to reveal their purple facets. 



The cr3'stals seem to have originated in 

 a bed or seam of vein-granite, in gneiss or 

 mica schist. 



The bed rock in which this vein occurs 

 is of a peculiar rusty-brown color, is much 

 broken up by joints, and oppears to consist 

 mainly of quartz and a little mica. I do 

 not remember to have seen any rock closely 

 I'esembling it elsewhere. 



Itiseasil3' recognizable after being once 

 examined, and I have traced it in a narrow 

 belt from the south end of Herring Pond 

 in a direction about south southwest, to a 

 point just be^'ond the " Battey place," a 

 distonce of nearly three miles. 



This rock is well seen where the Provi- 

 dence and Springfield Railroad cuts through 

 it, between Oakland and Horrisville. 



Amj'thysts of good size and shape have 

 been found at this point also, but they were 

 in the drift and were pale in color, some- 

 what marred and far less clear than those 

 farther south. Lumps of kaolin are also 

 found at this locality, with the crystals, and 

 probably originated fi'om the feldspar in 

 the vein-granite which held the amethysts 

 in its cavities. 



I had the exquisite pleasure at one time 

 of emptying a "■ pocket " of its amethysts in 

 a much decomposed block of this granite. 

 Some of these cr3'stals were clear as glass 

 and highly colored. In mon^' of the larger 

 specimens the color does not seem to be 

 evenly distributed through the crystal but 

 is in la^-ers parallel to the faces of the 

 pyramid, giving rise to " phantoms." 



I am not aware that any competent geol- 

 ogist has ever examined this locality care- 

 fully, but I think it would present some 

 points of interest to one who could inter- 

 pret its records, although the ground has 

 been dug over so much that it is difficult to 

 find any amethysts now. x. j. b. 



Native Forest Trees of Rhode Island. 



Number XIX. 



BY L. W. RUSSELL. 



A FINE specimen of American Barn Owl, 

 Strix pratincola, was taken at Sand Pond 

 about the third of this month, and on the 

 eighth Mr. Charles H. Lawton obtained, at 

 New[)ort, a very nice Razor-bill Auk, 

 Alca tarda. 



Tin-: Yellow Birch. — Betula excelsa. 



Thk Yellow Birch, Betula excelsa, helonga, 

 as a common forest tree, to regions having 

 a colder climate than that of Rhode Island. 

 It is found scattered in considerable num- 

 bers, however, in cool, moist localities in 

 this state. It is rarely' seen here, either in 

 open ground or as a forest tree, in its full 

 development. Farther north, in New Eng- 

 land and in Canada, it is in the woods, a 

 loft}' tree, rising sixty or sevent}' feet with- 

 out a limb, bearing a few feather^', spreading 

 branches, overtopping, usuall}^ the other 

 trees with which it is mingled. When grown 

 upon open ground from the start, it is a 

 wide spreading tree with a s^'rametrical or- 

 bicular head. In such a situation, the limbs 

 strike out low, are long and lithe, the 

 lower ones taking a graceful curve down- 

 wards. At first the limbs form very sharp 

 angles with the main stem and with each 

 other ; but their slender habit of growth, 

 combined with their elastic qualit}' in vield- 

 ing to the winds and coming back to position 

 redeems the tree from any aspect of stiff- 

 ness. Indeed, it is a tree of notable grace 

 and beaut}', deserving a prominent place in 

 arboriculture. 



The tree is easily distinguishable from 

 other birches by its bark. The bark upon 

 the limbs, except the smaller spra}^, and 

 upon the body, unless the tree is old, is yel- 

 lowish, having a firm, silk}' luster. The 

 outer portions hang in thin plates, which 

 quiver even in a light breeze. Upon the 

 body of old trees the bark appears in dark, 

 ragged plates, easily broken off. 



The leaves of this birch are oval in shape, 

 somewhat narrowed, or slightly heart-shaped 

 at the base, coarsely serrate, and upon 

 short, hairy footstolks. They appear in 

 twos except near the ends of the spray, 

 where they are alternate. In the autumn, 

 they take on fine shades of orange and yel- 

 low. 



The catkins of the male flowers appear in 

 pretty, yellowish tassels with the opening of 

 the leaves. They are shorter and thicker 

 than those of the black birch. The female 



