10 



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 Virginia 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. 

 Linnaeus described it in 1763 as Pimis 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 Tsnga 

 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 Xew 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 Xew York," pub- 



