الفهرس 
The gross anatomyOnly 14 pages are availabe for public view
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Abstract
anatomy os’ the digestive systeem of two birds having different feeding habits namely, a granivoroas birdthe
domestic pigeon, CoEuaba livia donestica and a carnfvorous one- the Sgyp’ciawd fa lcoa, -Pa-Ec s -- timuclus Irupicoleol~
rais, have been investigated , This study vhaa revealed the fal2a~ing:
-C-r ass anatomy:-
1- The shage of t h e beek ~ h o wa~ a daptation to t h e
is short and p~inted whereas t h a t of the falcon is mch shorter, very strong its upper half is sharply pointed a;~d hook - shaped,
2- The tongue is much harder in t h e falcon %ha in tile
pigeon sad its anterior half is dark in colour, 1%
is moved in bath birds by laur pairs of extrinsic m:tscles, These are bettees developed and mare povierful
in the falcon thm in the pigeon,
3- The oesophagus is iio-bably lovlg in the plges~; being double the length of that of t h e falcon, Its ~ddLe
p a r t is dif8erentiated in tbe pigeon into a vae%L developed crop, This: is totally absent frorra. the
falcon,
3 - The stomch is diffc?rentiated in both birds i n t o a gla~ndular provent~iculus and a muscular ventsiculus ar gizzard. The gizzard is math more devefcped in the pigeon than in the falcon, It is in the pigeon
of the compound type i.e, having a t h i c k hard cuti c l e whereas t h a t of the falcon is of tke simple type i. e, having a weak muscular coat and s o f t
lining secreti.ons.
R pylosic valve guards, both b i r d s , opening
of the pylorus i n t o the duodenum.
6 - The intestine is divided in both birds i n t o the duodenum, I.dea3kelVs t r a c t and s e c t urn, While i’leckel ’s diverticulum which difFerent iales Yeckel s tract in45; a proxiinal and a dis-ta% l i m b , is weLf d.eveHoiped in the falcon it is i n d i s t i n g u i s h a b l e in the pigeon,
7 - The rectal caeca we ?aired and too reduced in size i n both birds, 8 - The relative length of t h e pigeonPs intestiae rmges from ll,5-E whereas that of the falcon ranges from 5-6,
9 - The cloaca is differentiated in bath bird^ into three chambers, coprodaeua urodaeum and p~oclodaeuzi, The bursa Pabricii opens on t h e dorsal all
of the latter chamber is reduced in the adult, 10- The pmcreas cmsis&s in t h e pigeon, of a dorsal and a v e n t r a l lobe whereas t h a t of the Palcon is
a tripartite orgen, 3-1- The gall bladder is abaect fron %he pigeon bh%
well represented in the falcon,
12- In the pigeon one of the bile ducts opens into %he prowind 1;Cn’a of the duodenran and the other duct together with the three pmcreatic ducts open i n t o its distal limb, In the falcm, the two b i l e ducts of which Qne is diff erentiats into a hepats-cy&&~
asld cys-to-enteric toget her with the three pancrea- *c sl c d~ctso pen i n t o the ascending limb of the duodenum,
B - Bcroscoplr,aio~: 1 - The wall of the buccal cavity is compose6 in the +lIa -v-. birds of t h r e e layers: mucosa, Lined with a stratified squamous epi-Lhebium, a aubmcosa and. a. m~zscuiaris of fs;ngitv.di:?ally disposed striated
mscle fibres, Besides there is, in the pigeon, a thin Payer sf circularly disposed s t r i a t e d muscle
f ibrea , 2- Taste corpuscles are psesen-t in the roof and f l o o r
of the buccal cavity of both b i r d s as well as in t h e i r tongue. They are more abundant in t h e tongue
aZ the falcon than in that of t h e pigeon, 3- Well developed salivary glands Gccur in the antepior
and posterior regioiis of the roof arid floor sf the buccal cavity of both b i r d s . Beaides, Lingual salivary glands occur in t h e i r tongue, All these glands are DP the congaxad t a b u l a r type a~rd secrete mucus, 4- Ro glandular structures are enco~uztered in t h e
pharyngeal region of tke pigeon vhereas siaple alveolar mucous glands occu-r in that of the falcon, 5- simple branched alveolw glands are confined to t h e
lovier oesophagus of the pigeon whereas simple branched tubular ones occur in t h e lniddle alld lo we^ regions of the falcon % oesophagus. No gbandlnalr
structures are encour.tered in the pigeon’s crop. 6- The proventaiculus of t h e two birds possesses lu~-
naL simple tubular glsads as we11 as large - sized compov.~d tubular gastri~ glands, The latter are considerably thicker in t h e falcori than in the pigeon The cells of the gastric glands ase not differentiated into oxptic c e l l s , They however, produce hydrochloric acid.