1877.] BURSA FABRICII IN BIRDS. 305 
Prosector’s department have given me opportunities for examining 
this organ in a considerable number of species of birds of various 
orders ; and though I regret to say my investigations have not turned 
out so satisfactorily as regards taxonomic characters as I had hoped, 
I venture to bring such results as I have obtained before the Society 
this evening. As the subject of the bursa Fabricii has hardly 
attracted any notice in this country since the days of Harvey, I have 
added to my own notes a brief résumé of the most important ob- 
servations and opinions as regards its structure and functions that 
have been brought forward by foreign anatomists. 
The organ in question seems first to have been noticed by the 
naturalist whose name it bears, Fabricius of Acquapendente. In 
his treatise ‘De formatione ovi et pulli’', p. 5, he says :— Tertium 
quod in podice est adnotandum est duplex vesicula que in ima ejus 
parte ad os pubis supereminet, et conspicua exteriorque apparet, si- 
mulatque uterus jam propositus conspectui sese offert ; que cum sit 
pervia, ita ut ab ano ad ipsum uterum et ab utero in ipsam, ut puta 
superius, infra foramen pateat, ex altero autem extremo clausa sit, 
hune existimavimus esse locum, in quem gallus semen immittit por- 
rigitque ut inibi servetur.” From this and other passages in his 
works it is clear that he considered its function that of a receptacu- 
lum seminis in the female ; its use in the male, on sucha theory, he 
does not explain. Harvey, in his work ‘De Generatione Animalium ’ 
(London, 1651), as quoted in the Sydenham Society’s translation of 
his works (1847, p. 183), refutes Fabricius’s ideas on this point. 
“The foramen into which Fabricius believes the Cock to inject his 
fluid, is discovered between the orifices of the vulva and the rump. 
I, however, deny any such use to this foramen ; for in young chickens 
it is scarcely to be seen, and in adults it is present indifferently in 
males and females. It is obvious therefore that it is both an ex- 
tremely small and obscure orifice, and can have no such important 
function to fulfil; it will scarcely admit a fine bristle and needle, and 
it ends in a blind cavity ; neither have I ever been able to discover 
any spermatic fluid within it, although Fabricius asserts that this 
fluid is stored up there even for a whole year, and that all the eggs 
contained in the ovary may be thence fecundated, as it is afterwards 
stated.” Harvey, however, fell into error in asserting that in “ young 
chickens it was scarcely to be seen ;”? as we shall afterwards see, it is 
developed more in young than adult birds. This fact was first 
pointed out by Tannenberg in 1789, in his disquisition ‘ Circa geni- 
tales partes mascularum avium’ (Gottingee), and has subsequently 
been recognized by most authors who have written on the sub- 
ject (wide Cuvier, Milne-Edwards*, and Gegenbaur‘). Barkow, in a 
paper ‘‘ On the Cloaca of birds”? in Meckel’s ‘ Archiv ’*, describes 
its condition in specimens he had examined of the Fowl, Duck, 
' Hieronymi Fabricii ab Aquapendente opera anatomica, Patavii, 1625. 
2 Lecons d' Anatomie comparée, 2nd ed. vol. viii. p. 276. 
3 Physiologie et Anatomie comparée, vol. viii. p. 514, and vol. vii. p. 347, 
* Vergleichende Anatomie, p. 799, note. 
® Archiv, 1829, p. 443 e¢ seq. 
Proc. Zoor. Soc.—1877, No, XX. 20 
