211 
to another, except by some of the agencies above indicated. Our obser- 
xd Mr. Hubbard in Florida, and given in the special report 
= distribution of the particular species in question, all go to confirm 
of these m 
oH lady-birds (Coccinellide), and more particularly gossamer spiders, 
active agencies in such distribution. The agency of the wind, as 
indicated by the more rapid spreading in the direction of prevailing 
winds, has often been verified. Mr. Coquillett reports; “In the infested 
* part of this city (Los Angeles) is a large vineyard, and on both the 
Y Eh and south sides of it is an orange orchard infested by these 
“ insects; but, while the recently-hatched pee occur on the vines as 
** far out as the tenth row of grape vines on the south side of the vine- 
* yard, they are not found upon the vines MALI the third row on the 
* north side, the wind, as stated above, blowing from the south-west. 
: young inse nust have been carried by the wind from th 
“ infest nge tr either side vineyard 
experience in California showed that similar evidence of influence 
of the prevailing wind in promoting the sp the species is general. 
While Mr. Hubbard's observations sho the action the wind 
is indirect rather than direct, by influencing the pager of winged site 
and the floating of spiders which transport the scale-insects, yet 
have every reason to believe that winds have dies more direet Seow 
than is generally supposed, especially in the case of severe storms pass- 
ing over infested districts at the right season. We laid emphasis on this 
in our earlier writings, and Mr. Coquillett, while admitting the influence 
of birds, insects, and water in the transportation of our Zcerya, lays 
reatest stress upon the direct agency of the wind, Young scale-insects 
are not easily dislodged, but where a tree is badl y infested there is every 
reason ie. believe that they instinctively drop from the term inal twigs, 
and their specifie gravity is so slight, that they may be carried long 
dish | in strong wind cur 
In to the rbd of birds upon the spread of the Cottony 
Cushion- sale Mr. Coquillett sated that whenever the nest of a 
bird is found upon a tree recently infested with this insect, the latter 
doubt also that the irrigating ditches have a very marked influence on 
the spread o$ ine species, as many of the ditches pass under infested 
trees, and the y secretion serves both to protect the insect from the 
water and to facilitate floating. 
While, therefore, the gradual prend from ronem. to orehard is in the 
main through the agency of other flying insects samer spiders, 
yet the transportation of the pests to long distances ET necessarily be 
effected through the agency of high uds birds ga man in EON 
intercourse, the latter being probably the only 8 by which the 
species have been introduced from one country to pe an by 
wide ocean areas. 
NATURAL ENEMIES. 
Bırps.—The natural enemies of the Cottony Cushion-scale seem to 
be very few in number, not only in California but also in South Africa 
and New Zealand. In South Africa the only bird which is recorded as 
