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made for specimens of the insect upon neighboring trees of other varie- 
ties. The entire part of the grounds in the vicinity of the trees was 
searched without result, and the superintendent of the grounds assures 
us that no changes have been made in the surrounding vegetation 
since the peach plantation was started. The only plants in the imme- 
diate vicinity are a large evergreen hedge, an Osage orange hedge, 
some young fig trees, and afew grape vines, in addition to the ordinary 
couch grass and clover, and a few chenopodiaceous weeds. It is pos- 
sible that the young larve may have been brought from a distance 
upon the feet of birds or upon winged insects, but it is hardly possible 
that the species, if occurring in any numbers, should not have been 
discovered, even a block or more away. Later it was found that 
although the peaches were all seedlings, a few very small twigs and 
buds had been brought from Delaware for inoculation purposes by Dr. 
Erwin F. Smith, and a few more from Still Pond, Md. This introduces 
the possibility that the insect may have been brought upon these small 
pieces of Peach, but Dr. Smith is a very keen observer and has paid a 
great deal of attention to insects, and he assures us that the specimens 
brought were not affected by this insect. Moreover, he has, he says, 
a most intimate acquaintance with the orchards from which the twigs 
and buds were brought, and that the occurrence of the Diaspis in 
either of these orchards would certainly have attracted his attention. 
The origin of the infection on the Department grounds is, therefore, 
still obscure. 
A similar attempt was made to ascertain the origin in the cases of 
Mr. Harvey and Mrs. Johnson, and it was learned from correspondence 
that in the former case they first made their appearance upon some 
young trees, Peach and Plum, which he had received from California 
about February, 1888. They were set out and made good growth that 
year, but upon looking them over in the fall he discovered some dead 
wood and even dead branches covered with scales. He cut off the 
dead wood and washed the trees carefully, as he found the seale upon 
all parts. During the summers of 1889 and 1890 whenever he found a 
tree infested, he took it up and burnedit. During the winter of 1890-91 
he gave orders to have all the California peach and plum trees cut out. 
They were set out in a pear orchard, with no other peaches or plums 
in the immediate neighborhood. Something over one hundred were 
thus destroyed. In 1892 he found several large two and three-year 
old peach trees covered with the scale. They were half a mile from the 
spot where the California trees had stood. In the early part of 1893 
he found the insect scattered over the orchard; not on all the trees, 
but here and there throughout an orchard of two to three thousand 
trees. In September it had made very considerable progress. Up to 
June he had no doubt that he had brought the scale from California, 
but during that month he visited several orchards 80 miles to the 
east, and found the scale at that point. He was informed that none of 
