120 
PROCEEDINGS OF THE PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
the whole of these were associated under what was now 
called “ The Yorkshire Union of Natural History Societies. ” 
This Union still left the independence of each Society to 
itself, and it had, he thought, about four meetings every 
year, at which members of any Society could be present, 
while each Society was represented by delegates. One special 
feature of these meetings was that the whole business of the 
Union was discussed, the object of the Union being the 
investigation of the natural history of Yorkshire. There 
was another Union, namely, the Midland Counties Natural 
History Societies, that bad also been very successful. 
He believed they would all agree with him when 
he said that if they and similar Societies in the East 
of Scotland were united, they would be able to do 
more work and promote their general objects more 
effectually. He was last summer brought into con¬ 
tact with members of Natural History Societies in Dundee 
and Arbroath, and in the course of conversation 
some of the members, especially those of the Dundee 
Naturalists’ Society, took up the subject very heartily. 
The outcome of the matter was that he had had a letter the 
other day from the Secretary of the Dundee Naturalists’ 
Society, sayiDg that he, Mr Erank Young, and Mr J. 
Martin White, yr. of Baldruddry, had been appointed a 
Committee to come to Perth to discuss the question with 
him. Now, he thought it would be much better that 
their Society should appear officially in the matter by ap¬ 
pointing him as a member of the Committee, and perhaps 
some other member; so that they would not be outvoted 
by the Committee of the Dundee Society, when they met 
to discuss the question of the Union. He thought they 
could not appoint a better member than then- delegate to 
the Committee of the British Association, who had studied 
the question of the working of Local Natural History 
Societies ; — he meant Mr .Robert Pullar. His idea 
on the subject was that the Societies included in the 
basin of the Tay, and perhaps—as Societies in Scotland 
were not so numerous as they might be—all the Societies 
in the basin of the Dee and Don, might form a Union of 
the East of Scotland, the primary object of which would 
be the investigation of the fauna and flora of that part of 
the country. Perthshire did not include the mouth of 
the Tay; so the Dundee Society would cover that ground. 
He thought that these would very naturally form a fitting 
union of Societies. As to how the scheme would be carried 
out, he thought that possibly they might have, in different 
places in rotation, an annual meeting, where the objects of 
the Union might be discussed, an excursion made, and so on, 
and thus promote good fellowship among the different 
Societies; and by seeing what the other Societies did, it 
might be a means of spurring themselves on to greater 
efforts. 
Mr Robert Pullar said that he had had the honour of 
acting as delegate of the Society to the British Association 
at Southport. He met there a large number of gentlemen 
who were connected with Local Societies in England 
and Scotland, and they all spoke of the great benefits 
derived from forming District Associations. They could 
not have done half the amount of work had they not been 
associated in groups. One of the objects of these District 
Associations, too, was to associate themselves with the 
greatestAssociation in Britain—th e British Association; and 
he was glad to think that their Society should be associ¬ 
ated with it in the future. One point that the British 
Association was determined upon was, that they would 
have no Local Natural Science Society that did not do 
some work, and publish their proceedings every year 
or two years; — so that, if they expected to continue 
to have the honour of being connected with the British 
Association, it must be understood by the members that 
some work must be done;—and he thought that it was a 
very proper thing to want only working Societies connected 
with them. There would be various benefits derived from 
being connected with this great Association which be need 
not dwell upon, but he would ODly say that he should be 
very glad to act along with Dr White in the matter to 
which he had referred. 
Mr A. Coates said that the proposition was a most 
interesting one, and one that would strengthen them in 
their work in every way. They could not do better 
than take this preliminary step towards anything further 
they might do in the matter. 
The motion was unanimously agreed to. 
The following paper was read :— 
“ Dimorphism in Oak Gall-Makers, and in their Galls.'' 
By Professor J W. Trail, M.D., E.L.S., Aberdeen. 
The subject on which I propose to address you to-night 
was, like so many others in the domain of biology, almost 
entirely unknown, even unsuspected, a dozen years ago. 
It has, within the past five or six years, come prominently 
forward, as the result of the very careful and painstaking 
observations of certain entomologists, chiefly in Germany 
and in France; and it has been found to explain mysteries 
in the life-history of not a few long-known species of gall- 
makers,—mysteries that had long baffled the conjectures 
of all that had given their attention to insects that have 
been regarded, by most entomologists even, as of too little 
