. The structure and classification of birds . arger than the left, andthe gall bladder may beabsent or present. In the Columbsewhich I have examined(Columbm of severalspecies (fig. 156), Fhlo-gcenas cruentata), re-marks Mr. Mitchell, it is tempting to regardthe gut as a simple deri-vative of the type seenin Fterocles. The duo-denum is longer andnarrower. The circularloop is enormously ex-panded, but the threesubsidiary loops seenin Fterocles remain. The first of these is somewhat shortened;the second, that- bearing the yolk-sac vestige at its end, isenormously lengthened ; the mesentery is fol
. The structure and classification of birds . arger than the left, andthe gall bladder may beabsent or present. In the Columbsewhich I have examined(Columbm of severalspecies (fig. 156), Fhlo-gcenas cruentata), re-marks Mr. Mitchell, it is tempting to regardthe gut as a simple deri-vative of the type seenin Fterocles. The duo-denum is longer andnarrower. The circularloop is enormously ex-panded, but the threesubsidiary loops seenin Fterocles remain. The first of these is somewhat shortened;the second, that- bearing the yolk-sac vestige at its end, isenormously lengthened ; the mesentery is folded along theline of the median mesenteric vessel, so that the two limbsof the loop are brought in contact with each other, and,finally, the whole folded loop is rolled into a rough third subsidiary loop of the circular part of the gut has E. Gekmain, NDtesurla Structureiu Gfeierohez le Pigeon Nioobar, Ann-Sci. Nat. (5), iii. p. 352; Gabkop, . Note on the Gizzard and other Organs latrans, P. Z. S. 1878, p. 103. : X 2. Fig. 156. —Intestines of Columba Uvia(aptek Mitchell). 308 STRUCTURE AND CLASSIFICATION OF BIRDS the same arrangement and veins as in Pterocles ; bijt thecaeca no longer run along it, but occur as very short stumpsupon the rectum. The cmca are small and nipple-like; they may be entirelyabsent. In Tympanistria bicolor I found one, an especiallyminute one, on the left side. The intestines of the Columbse are very short and volu-minous in some of the fruit-eating forms, moderately long inthe majority of forms, and extraordinarily long in Bidun-culus. The following are a few measurements :— Ft. Ins. Ft. Ids. Garpophaga cenea . 1 6 Chrysoena viridis . 7 Ghalcophaps chryso- Macropygia lepto- chlora. 1 8i grammica . 2 lOi Phlogoenas Stairi . 2 6 Peristera Geoffroyi 10 „ cruentata 2 H lanthoenas leuco- Columba maculosa . 2 8 loema 3 11 Geopelia cuneata . 8i Goura coronata 5 1 „ humilis 1 6 „ Victoria 4 0 Ptilopus jambu 1 0 Phaps chalchop
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbirds, bookyear1898
