54 PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 
recommended the importance of the introduction of the Japanese 
parasites, and Dr. Felt suggested the importance of careful biolog- 
ical studies of the parasites, not only in America but in Europe, All 
of these suggestions coincided with plans already made which were 
about to be entered upon, as indicated in following pages. 
The subject of the study of the diseases of the caterpillars does not 
come under the range of the present bulletin, but since it- has been 
mentioned, it should be stated that the State superintendent has for 
the past two years been having this subject investigated and that it 
is now going on under the expert supervision of Dr. Roland Thaxter, 
of Harvard University, and Dr. Theobald Smith, of the Harvard 
Medical School. 
Mr. Kirkland’s summary seems fully justified. It is as follows: 
It will be seen from the foregoing that the work of importing parasites of the gipsy 
and brown-tail moths in Massachusetts has been thoroughly examined by practically 
a congress of the world’s leading entomological experts. And it is believed that their 
consensus of opinion, which is, in the main, that everything possible to secure the 
successful importation of these insects is being done, will be taken as authoritative 
and final. It would seem that the last word has been said on this matter, and that 
there should be no further occasion for that kind of adverse criticism, whose sole 
effect is to harass those who are giving their best thought and most sincere effort to the 
accomplishment of the desired result. Destructive criticism of scientific work, by 
the amateur or dilettante, is absolutely valueless. Constructive criticism, such as 
these reports make on certain minor details of this important work, is helpful and a 
public good. 
NARRATIVE OF THE PROGRESS OF THE WORK. 
Down to the time when this work was begun, all attempts at the 
international handling of beneficial insects had been done either by 
correspondence or by the sending of an individual collector to search 
for such insects and to forward them by mail or express or to bring 
them back himself in comparatively small numbers, the beneficial 
species being either at one? liberated in the field or reared for a time 
in confinement and then liberated. In planning the present work 
the normal geographic ranges of both the gipsy moth and the brown- 
tail moth were well known and most of their parasites had been listed, 
so that the problem seemed to be a comparatively simple one. Owing 
to the fact that the most abundant of the Japanese gipsy moths (four 
of them are listed) presents rather marked differences from the Euro- 
pean and New England form—so much so, in fact, as almost to justify 
the opinion that it is a distinct species—and as the ancestors of the 
New England gipsy moth came from Europe, it was decided to con- 
centrate the effort, for a time at least and in the main, upon Euro- 
pean parasites and natural enemies. From the outset the idea was 
to secure as many parasites belonging to as many different species as 
possible from all parts of Europe, in the hope of establishing in New 
England approximately the natural environment of the gipsy moth 
