 | John Jacob Thomas - 1878 - 360 páginas
...Secondly, although insects, or remains of insects, are generally found in old knots, in most cases no marks at all are found in them when young. Thirdly, the...several different species, which are also found on trees which are never affected by the knot. On the other hand we never have the black knot without the Sphceria... | |
 | Michigan State Horticultural Society - 1883 - 486 páginas
...disease is caused by insects: First the knots do not resemble the galls made by any known insects. Secondly, although insects, or remains of insects...other hand, we never have the black knot without the Splmria morbosa (the scientific name of the fungus), and the mycelium of that fungus is found in the... | |
 | Pennsylvania. State Board of Agriculture - 1884 - 734 páginas
...knot is not caused by insects: First, the knots do not resemble the galls made by any known insects. Secondly, although insects, or remains of insects...other hand, we never have the black knot without the Sphaeria morbosa, and the mycelium of that fungus is found in the slightly swollen stem, long before... | |
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Secondly, although insects, or remains of insects are generally found in old knots, in most cases, no insects at all are found in them when young. Thirdly, the insects that have been found by entomologists in the knots are not all of one species, but... 