Dr. Latruam’s Effay on the Trachea or Windpipes of Birds. 9 
of our attention, asit is only at particular feafons that fome of them 
are to be met with, and feveral in mild winters do not vifit this 
kingdom, except by feeming chance, or in very fmall numbers, It 
is not poffible therefore that any perfon of himfelf, however advan- 
- tageoufly fituated, can hope to meet with a fufficient number of 
f{pecimens, without the affiftance of others. I fpeak this experi- 
mentally, as without fuch aid 1 fhould not have been able to have 
furnifhed matter for this effay. 
Amongft the various friends to whom I am obliged in refpe& to: — 
this undertaking, the judicious and well-informed Naturalift,William 
Boys, Efq. of Deal, ftands defervedly foremoft, having rendered me 
very great affiftance, not only by {pecimens, but by every obferva- 
tion in his power.. I find myfelf greatly indebted to my friend Co- 
lonel Montagu, a moft diligent obferver of nature; alfo to Mr. Lamb, 
Surgeon, of Reading—all Fellows of this Society. Nor fhouldI omit 
my valuable correfpondent Dr. Bloch, of Berlin, who has rendered. 
-himfelf con{picuous by feveral eflays on the prefent fubject, as may 
be feen in the Berlin Tranfactions*.. To which muft be added the 
obfervations of DoctorsPallas+, Beckmann, Silberfchlag§, and Otto}; 
contained in the fameworks, all of which may be read to advantage ; 
for although thefe gentlemen do not altogether coincide in their 
- opinions, yet as they all tend to the fame point, fuch efforts in order 
to afcertain truth muft always be ufeful—Not forgetting due ac- 
knowledgment to the valuable paper of the late Dr. Parfons, who, 
many years prior to. the above, gave an account of the fructure of 
the a/pere arteria, or windpipes, of feveral Birds, and in the Land 
* Befch: der Berl. Nat. Fr. iv. p. 579.—Schrift. der Berl. Nat. Fr. i, p. 51. 
+ Befch. der Berl. Nat. Fr. ii. p. 551. 
$ Befch. der Berl. Nat. Fr. i. p. 170. 
§ Schrift. der Berl. Nat. Fr. i. p. 36. 
ft Bech. der Berl. Nat. Fr. iii. p. 456: 
N 2. Tortoile, 
