PERIODICAL PHZ NOMENA OF ANIMALS AND VEGETABLES. 331 
P tions are made; and it is just these corrections which will, I hope, serve to 
' show the utility of the work which we are desirous of seeing undertaken in 
the greatest possible number of localities.” 
Birds selected for the observations. (See this List at the end, as amended by 
the Committee for the use of English Observers.) 
M. de Selys thinks the determination of the period of departure needs less 
to be insisted upon, being aware of the great difficulty attending it; how- 
- ever, exceptions should be made, especially'in the case of swallows, quails, 
wagtails (Mot. alba), and the crow. 
To the observations on the arrival and departure of birds, we may advan- 
tageously append those which M. Cantraine proposes :— 
Of the period at which ‘crows, starlings ( Sturnus vulgaris, L.) form into 
flocks, or pair off; 
Of the period at which the magpie (Corvus pica, L.) commences its nest ; 
Of the period of moulting ; 
Of the period at which the sparrow (Fringilla domestica, L.) selects a 
companion, a time remarkable for scenes of quarreling, which are often more 
readily distinguished by the ear than the eye. The period at which it begins 
to build should also be noticed. 
The thrush Whe: musicus), the field-fare (Turdus pilaris) and the 
missel thrush ( Twrdus viscivorus) deserve particular attention, inasmuch as 
they are regular birds of passage throughout the greater part of Europe. 
_ These birds are also the more readily observed, as, being in request for the 
table, they are found in all the markets. 
As M. Cantraine has observed, “ we should point out, as far as possible, 
the local circumstances which may cause any species to prolong its stay in 
any particular place. Thus, on the 9th of October 1841, swallows were still 
in immense numbers in the vicinity of the north and south stations on the 
Brussels railroad, whereas they had quitted Ghent about the 17th of Septem- 
ber, and but few individuals were to be seen at Ath on the 25th of that month. 
Should not this long stay be attributed to a more elevated temperature, 
caused by the locomotive engines stationed there, as well as to a greater 
abundance of food, the consequence of this?” 
The naturalists of the south of Europe will not allow the arrival and de- 
parture of the flamingo (Phenicopterus antiquorum), nor of some species of 
 sea-gulls (Larus melanocephalus, &c.), nor of the tunny (Scomber thynnus), 
_ to escape their attention. A. QuETELET. 
Brussels, December 1, 1843. 
_ N.B. Such persons as are desirous of taking a part in these researches, are 
_ requested to address their results to Mr. noe the Assistant Secretary of 
_ the British Association, to the care of Messrs. R. & J. E. Taylor, Red Lion 
- Court, Fleet Street. 
List of Plants to be observed for the periods of Foliation and Defoliation. 
_ Acer campestre, L. Amygdalus persica, Z.(@,Ma- Carpinus betulus, Z, 
_ +—  pseudo-platanus, Z. deleine). —— orientalis, Z. 
_ ——saccharinum, L. Aristolochia sipho, Z. Celtis cordata, Desf. 
_ — tataricum, L. Betula alba, L. orientalis, Z. 
_ Aisculus hippocastanum, L. alnus, J. Cercis siliquastrum, Z, 
— lutea, Pers. Berberis vulgaris, Z. Chionanthus virginica, Z. 
_ — pavia, L. Bignonia catalpa, L, Corchorus japonicus, Z. 
_ —— macrostachys, Mich. radicans, Z. » Corylus ayellana, Z. 
"i Amygdalus communis, Z. Carpinus americana, Mich, | —— colurna, ZL. 
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