![Comparative anatomy and physiology. Chap. VI.] GILLS OF FISHES, 233 the gill sacs open separately to the exterior, but in the hag the ducts unite and open by a common orifice Comparative anatomy and physiology. Chap. VI.] GILLS OF FISHES, 233 the gill sacs open separately to the exterior, but in the hag the ducts unite and open by a common orifice](https://c8.alamy.com/comp/REFHE7/comparative-anatomy-and-physiology-chap-vi-gills-of-fishes-233-the-gill-sacs-open-separately-to-the-exterior-but-in-the-hag-the-ducts-unite-and-open-by-a-common-orifice-on-either-side-a-similar-modification-obtains-in-the-gnathostomatous-fishes-for-in-the-shark-like-elasmobranchs-sharks-and-rays-each-gill-cleft-is-open-to-the-exterior-while-in-chimsera-and-all-other-fishes-the-clefts-are-covered-over-either-by-a-fold-of-the-skin-merely-or-by-bony-pieces-opercu-luin-so-that-there-is-on-either-side-but-a-single-opening-to-the-exterior-the-gills-when-complete-consist-of-two-f-REFHE7.jpg)
Comparative anatomy and physiology. Chap. VI.] GILLS OF FISHES, 233 the gill sacs open separately to the exterior, but in the hag the ducts unite and open by a common orifice
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European Honey Bee (Apis Mellifera) with Pollen Sacs Flying Towards a Scentless Mayweed Flower, UK' Photographic Print - Fergus Gill | Art.com
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