Io 
method of cooperation the hemlock and many other trees receive 
a large share of their nutrition, and are not healthy if deprived of 
the mycorrhiza. 
The Canadian hemlock spruce was discovered by the earliest 
European settlers of New England and was well known to them, 
as appears frequently in their literature, but it seems to have been 
first botanically noticed by Plukenet, in his Phytographia, pub- 
lished in 1691, where he calls it “ Abies minor pectinatus foliis 
virginiana, conis parvis, subrotundis,” and gives a very crude 
illustration of its leafy twigs and cones. The tree known to him 
was cultivated in the garden of Bishop Compton in London, who 
is recorded as having received it from V irginia through John 
Bannister, a collector of American plants. Philip Miller, writing 
in 1742, says that this tree had then been destroyed, but that the 
species had been “ retrieved ” through seeds sent him from New 
England, and it soon became well known in European gardens. 
Linnzeus described it in 1763 as Pinus Canadensis and it was thus 
known by many subsequent authors; the French botanist and 
traveller, Michaux, recognized the tree as more nearly related to 
the firs, than to the pines, agreeing in this with the opinion of 
Plukenet, and in 1803 named it Abies Canadensis, and this name 
has also been used for it by many writers. In 1855 Carriere, a 
distinguished French student of coniferous trees, published a work 
in which he carefully described all of them known to him, and 
showed that the hemlock spruces were sufficiently different from 
both pines and firs to be grouped as a separate genus, to which he 
assigned the name Tsuga, the Japanese name of the hemlock 
spruce growing in eastern Asia, specifying our tree as Tsuga 
Canadensis, and it has since been known under that name. 
The Bronx hemlock forest is the most southern considerable 
aggregation of these trees near the Atlantic seaboard. A few 
scattered trees and small clumps or groves grow or have grown 
naturally at other points in the borough, especially along the 
Bronx River further north and in the vicinity of Riverdale and 
elsewhere near the Hudson River; they become plentiful on the 
sides of valleys and ravines in Westchester County and in western 
Connecticut, as also in northern New Jersey, and from these re- 
gions northward into Canada the hemlock is an abundant forest 
tree; further west it grows plentifully along the whole Appa- 
lachian Mountain system as far south as Alabama, and its extreme 
western range is found in Minnesota and Wisconsin. 
Torrey records in the “ Catalogue of Plants Growing Spon- 
taneously within Thirty Miles of the City of New York,” pub- 
