196 Recent Ornithological Publications . 
be attained. I therefore counsel any one desirous of giving effect 
to Mr. Wolley's idea to begin by polling the Partridges. 
There is one other point on which I would say a few words 
before concluding these remarks, and that is, on the great caution 
requisite not only in making the observations themselves, but 
also in drawing inferences from them. Scarcely any one is aware, 
until he has tried for a long time, how hard a thing it is to 
observe correctly. I have taken no small pains in this matter for 
some years, and the chief result is that I have learned to doubt 
many of my earlier observations, and consequently not to place 
implicit confidence in my later ones. As to the inferences, it is 
an old saying that anything may be proved by statistics, and a 
true one, if the statistics be not collected and worked up with the 
utmost fairness. It seems to me that the mere arrival at what an 
ordinary observer may fancy to be an approximate enumeration of 
the individuals of a species is not so very difficult. The danger 
to be guarded against lies in the not making sufficient allowance 
for the effects of causes, which I would call the disturbing forces, 
having an origin entirely independent of ornithology, such as 
unwonted abundance or dearth of food,—seasons, wet or dry, cold 
or hot, beyond the average. These must always exercise more 
or less influence on its numbers, while their continued variability 
makes their influence only to be duly appreciated by an observer 
of prolonged experience. With these considerations I leave the 
subject to the readers of f The Ibis/ 
Elveden, 4th March, 1861. 
XXL —Recent Ornithological Publications. 
1. English Publications. 
We have little doubt that most of our readers are already well 
acquainted with Mr. Tristram's work on the “ Great Sahara*,” 
which will indeed require no recommendation to those who have 
read that gentleman's lifelike sketches of a portion of his travels, 
and his interesting notes on the birds met with “ south of the Atlas 
Mountains,” already published in this Journal. As, however, 
* The Great Sahara: Wanderings South of the Atlas Mountains. By 
H. B. Tristram, M.A., F.L.S., &c. 1 vol. 8vo. London, 1860 (Murray). 
