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1911] Botanical Lectures at the Lowell Institute 253 
British America north of the Arctic circle and Greenland (Hook. Arc. 
Pl.)” 1 but Bebb remarks: “I have not seen specimens.” ! It is not 
improbable that Hooker's British American plant was S. calcicola, 
from which S. lanata is distinguished by its more elongate and pubes- 
cent leaves, its longer aments with more colored hairs, and by the 
2-cleft stigmas. 
STUMP-HEALING IN Pinus STROBUS.— A few years ago I noticed a 
white pine stump which was healing over! This was contrary to all 
experience. For such growth is uncommon or rare on low stumps 
even among our dicotyledons which ‘sucker up’ freely. And Pinus 
Strobus never grows again from the stump,— P. rigida being our 
only conifer that behaves in this manner. The tree had been cut 
about four years apparently, and during this time the wound-tissue 
had spread inward irregularly over the cut surface, in places nearly 
an inch. How could a leafless plant do this? But one answer was 
possible,— that nourishment was being derived from some other tree, 
and root-grafting was suspected as the means, though such could not 
be proved at the time. Later a similar growth was noted on a small 
hemlock stump in the Arnold Arbcretum. This summer another 
case has come to my attention, and has supplied evidence showing 
that root-grafting is indeed the cause cf these unusual growths. One 
pine among a group was cut, and the stump healed slowly for two or 
three years before dying. These trees stand on a gravelly knoll and 
their roots are nearly all exposed for some distance from the trunks. 
Grafting frequently occurred where crossings were formed, especially 
along a path where the roots bad been wounded. It is probable that a 
parasitism of this sort is not uncommon among our trees, but the sight 
of an apparently lifeless pine-stump magically healing itself is almost 
startling.— ARTHUR J. Eames, Cambridge, Massachusetts. 
BOTANICAL LECTURES AT THE LOWELL IwsriTUTE.— The Lowell 
Institute announces among its courses of free public lectures a series 
on Local Natural History to be given under the auspices of the Boston 
Society of Natural History. The series upon “The Wild Plants of 
Eastern Massachusetts " is to be given by Professor M. L. Fernald on 
! Bebb, Bot. Gaz. xiv. 49 (1889). 
