El rymen to comply with the American quarantine regula- 
Beene The request of te deeded authorities—the English nur- 
series were inspected throughout the Summer and after Oct. 1 and health 
certificates, in the form prescribed by the American regulations, issued 
to the effect that plants therefrom were found, or believed by the inspector 
to be free from injurious plant diseases and dangerous insect pests. 
What English Health Certificates Mean 
A little reflection will be sufficient to show that many minor pests 
are bound to be present on plants in nurseries, and if all these were 
taken into consideration no certificates could ever be issued. Prior to 
1921 in most instances the American authorities did not require or ask 
for an inspection of the plants at the time of packing, except in the case 
of stock shipped during the growing season, a point of some importance. 
The English health certificate has in the past been given to show that the 
nurseries in which the plants were grown were free from injurious plant 
diseases and dangerous insect pests (i. e., all British pests of any im- 
portance, and also all those scheduled under the Destructive Insects and 
Pests Order of 1910, e.g., Gypsy and Brown Tail Moths). It did not imply 
that the plants had been inspected and found to be free from all insect 
and fungus pests. 
It never has been clear to English pathological experts why the 
Americans did not insist on inspection also at the time of packing prior 
to 1921, and of the issue of a certificate of another character; possibly 
they may have deemed it unnecessary seeing that the plants were to pass 
a critical test at the quarantine station in America. Letters from the 
Department at Washington would indicate that in 1918 they had lost 
faith in the value of the health certificates because of the number of in- 
tercepted pests (in the case of England amounting to 62 pests in 154 
infested shipments.) Fortunately the American system is excellent in 
publishing quarterly letters, setting out details of these intercepted pests, 
and it is thus possible to visualize exactly the kind of pest in question. 
It would appear, then, that while the Federal Horticultural Board 
haye under Quarantine 37 been asking for nursery inspection and a 
health certificate of a certain kind, they have been expecting to receive 
plants entirely free from all insects and fungi—a quite different matter. 
The mere fact that many insects and fungi mentioned in the foregoing 
lists have been intercepted is no indication that the health certificate 
system has broken down—except in one or two isolated cases—or that 
the system is of no value. It does indicate, however, that the terms of 
the health certificate are a matter for consideration between the issuing 
countries and the Federal Horticultural Board. 
An examination of this list shows that three distinct classes of 
pest have been intercepted. The first-class, and by far the largest, com- 
prises pests cosmopolitan in distribution and abundant in the U. Ss. A— 
in most cases more abundant there than in Britain. The second class 
comprises a very few species resident in Britain, but not known to occur 
in the U. S. A., or at most only occurring in restricted areas. The third 
comprises species which are distributed by shipping and have no direct 
connection with the trade in live plants. Their presence in plant con- 
signments must be regarded as purely accidental, as equally likely to oc- 
cur on all merchandise and so without bearing on the present discussion. 
Intercepted English Pests Mostly Unimportant 
Of these three classes, 
obviously th imp i 
species resident in Britain Y vac Most important is Class 2— 
and non-existent or very restricted in the 
14 
