6o The Irish Naturalist March 
twenty tickets. These changes were seconded by ISIr. Longworth 
Dames and passed. 
Messrs. F. Gifford, J. IngUs, and Dr. Woods were elected to vacancies 
on the Council. 
Professor J. A. Scott gave an account of changes in the gardens during 
191 2, illustrated with a lantern and cinematograph display. 
BELFAST NATURALISTS' FIELD CLUB. 
November ii. — The President (Rev. Canon Lett) delivered an address 
on *' Botanists of the North of Ireland," which has already appeared in 
the Ivish Naturalist {supra pp. 26-33.) 
February 5. — Before the Botanical and Zoological Sections, R. Lloyd 
Praeger, M.R.I. a., gave a lecture entitled, "What do we mean by a Native 
Species ? " Robert Welch occupied the chair. In the course of his 
address, after pointing out the general character of the European flora, 
and tracing the progress of human interference with the pre-existing 
vegetation, and the various classifications of native and non-native plants 
which had been proposed, Mr. Praeger said the definition of a native 
species employed by Dunn in his "Alien Flora of Britain" requires us 
to ask three questions relating to the species under consideration. First, 
have the ancestors of it been in the district since prehistoric times ; 
secondly, did it reach its present habitat without the aid (either inten- 
tional or accidental) of man ; thirdly, is it living on ground which has 
been undisturbed by man ? If we can answer these three questions in 
the affirmative we may, according to Mr. Praeger's formula, regard the 
standing of the species as NNN in whatever area we may be considering. 
On the other hand, the standing of an alien plant brought from a corn- 
field, into which it was transported with seed by man, and planted in 
cultivated ground is regarded as ***. Between these two extremes we 
have six combinations of N and *. Thus the standing of an animal which 
has spread from a lake such as Lough Neagh into an artificial waterway', 
such as the Lagan Canal, changes from NNN in the lake to NN* in the 
canal. And, again, one brought by man from Lough Neagh, where it 
was NNN, and placed in an artificial pond becomes N**, An alien which 
in a garden would be *** becomes similarly *NN if it spreads by its own 
powers to undisturbed ground, or it becomes *N* if it spreads to cultivated 
gTound, or it becomes **N if it is carried by man and deposited in natural 
or undisturbed ground. In conclusion, Mr. Praeger suggested that only 
those animals and plants whose standing in any district can be regarded 
as NNN or NN* may be considered for general purposes to be " native." 
The Chairman having thrown the meeting open to discussion, many 
points arising from the lecture were raised by members, including Pro- 
fessor Gwynne-Vaughan, Dr. Dwerryhouse, A. S. Bennett, A. W. Stelfox, 
and others, and replied to by Mr. Praeger. 
