I860.] BRUNET— -ON THE GENUS PICEA. 105 



the wood of the species of Picea from that of any other 

 conifers. 



This wood is more subject to cracking than that of the white pine. 

 and is liable to shrink when not perfectly dried. It is, however, 

 much employed for flooring, on account of its greater hardness, 

 and is largely exported from Quebec in the form of planks. It is 

 also esteemed for its lightness and elasticity, for which quality it 

 is employed for the ship-yards. All the houses which, in the 

 country parts of Canada are made of hewn logs, and are known 

 as log-houses, are constructed of white spruce, which is also 

 employed for the frame-work of steeples, of bridges, etc. The 

 bark of the tree furnishes curved timbers, or knees, as they are 

 called, which are used for ship-building, although inferior to those 

 furnished by the tamarack (Larix Americana). The aborigines 

 make use of the tough rootlets, previously macerated in water, to 

 sew the seams of their bark canoes. 



The pyramidal form of this tree, the regularity and number of 

 its branches, and its abundant foliage, make the white spruce one 

 of the best of ornamental evergreen trees. It moreover adapts 

 itself to almost any soil, not too solid and compact, so that it is one 

 of the Canadian trees best fitted for plantations. The readiness 

 with which the white spruce throws out auxilliary buds renders 

 it fit for pruning, and enables us to make of it excellent hedges, 

 which may advantageously replace these of hawthorn. 



This sketch of the white spruce would be incomplete if we did 

 not mention a parasitic insect, which frequents it, and causes 

 the small galls which are often seen upon this tree. They may be 

 observed in the spring-time at the ends of the young branches, 

 where they are dark red in color, and resemble in miniature the 

 fruit cones. We met them for the first time at the end of May, 

 1863, on the island of Orleans, arid again some time later near 

 the Chateau Bigot, in the rear of Quebec. Baron Osten-Sacken, 

 after having examined the specimens which we sent him, informs us 

 that these galls are produced by a species of Aphis, hitherto 

 unknown to science. 



PlCEA NIGRA. 



The Picea nigra is even more widely spread in the north of 

 America, than the preceding species, for it is found farther 

 to the northward, and beyond the Saguenay, in elevated localities, 



