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August 7, 1844. 



Dr. Storer, Vice President, in the Chair. 



Rev. J. L. Russell read a report of his observations and 

 conclusions respecting the disease of the button wood tree. 

 After a general description of the phenomena attending the 

 loss of the foliage, and mentioning the causes to which it 

 has been attributed, such as worms gnawing the leaves, 

 aphides, psoci, scolyti, fire blight, &c., he proceeds : 



In order, if possible, to discover the cause, I cut some healthy- 

 twigs of the previous summer's growth, on March 7th, and found, 

 that even then, many of the buds were already dead, and below 

 these, and some of the other buds also, a streak of incipient decay 

 was to be seen. This streak of decay, examined by a powerful 

 achromatic lens, exhibited no presence of fungi, or, indeed, any 

 immediate cause of death to the tissue. In some of these buds I 

 found ova of insects, — and in a dead spot on a twig, beneath the 

 bark, I extracted a very minute larva ; and from a sketch of it 

 which I showed Dr. T. W. Harris, it was pronounced as probably 

 that of a Psocus, an insect infesting only diseased or decayed wood 

 and bark. It is to be observed, also, that on the decay of the bark 

 and buds, innumerable minute swellings are to be found on the ex- 

 terior of the twigs, which are a species of Fungus, also always 

 present in the decaying wood or bark of a great variety of trees 

 and shrubs, belonging to the genus Stromatosphceria, but as in the 

 case of the Psoci, not the cause of the disease. 



The winter of 1843-4 was unusually cold, and destroyed vast 

 numbers of fruit trees in some sections of the vicinity of Boston. 

 These fruit trees exhibited a similar appearance to that of the But- 

 tonwoods, except that in their case the result has been fatal. Young 

 peaches, cherries, pears, have gradually died, even after leafing, 

 flowering and setting their fruit. In fact they were winter killed. 

 I think that this is the condition of the Buttonwood trees about Bos- 

 ton. Well-ripened wood is always essential to vigorous health in 

 perennial vegetation. For several years no such young wood has 

 been seen in these trees. Neither have they produced any flowers 

 since the disease was noticed, excepting a few in the year 1842. 



PROCEEDINGS B. S. N. H. 21 NOV. 1844. 



