File:Outlines of comparative physiology touching the structure and development of the races of animals, living and extinct - for the use of schools and colleges (1870) (14802610283).jpg

Identifier: outlinesofcompar00agas (find matches)
Title: Outlines of comparative physiology touching the structure and development of the races of animals, living and extinct : for the use of schools and colleges
Year: 1870 (1870s)
Authors: Agassiz, Louis, 1807-1873 Gould, Augustus A. (Augustus Addison), 1805-1866 Wright, Thomas, 1809-1884
Subjects: Physiology, Comparative Zoology
Publisher: London : Bell & Daldy
Contributing Library: MBLWHOI Library
Digitizing Sponsor: MBLWHOI Library

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
ular bag, provided with a duct opening into thefunnel. This fluid is secreted in great abundance, and beingvery miscible with water, forms a black cloud when injectedinto the sea; and by means of this singular provision thesenaked, defenceless animals are enabled to elude the pursuitof their numerous enemies. The inky fluid, abounding iu 172 ORGANS OF DIGESTION. carbon, may probably be the excrementitous portion of thebiliary secretion, eliminated from the system by a distinctorgan, and thus made to serve a double use ; it may, in fact,be analogous to that portion of the bile which is carried di-rectly out of the body by a separate canal in the Doris. (§ 322. In the ANNELIDA the digestive tube passes straightthrough the body. The mouth is provided with jaws, and theglands of the intestine are in the form of lateral caecal appen-dages. The circulation is carried on by arteries and veins;their blood is red, and their respiratory organs are in the formof branchiae, or internal air sacs.
Text Appearing After Image:
Fig. 178.—The anatomy of the Hirudo medicinalis. (§ 323. The Leech (Hirudo medicinalis, fig. 178) has a trian-gular-shaped mouth (a), armed with three small teeth, a pharynx,composed of numerous muscles (c); the action of which is seenwhen the animal is engaged in sucking; the pharynx opensinto a very large capacious sacculated stomach, with mem-branous parietes, united by small folds to the enveloping elastictunic. The stomach is divided into numerous separate cham-bers (/>/,//,/), by transverse processes of the lining mem-brane, communicating with each other by central oval open-ings ; it extends through about three parts of the entire lengthof the body, where it enters the intestine (m) by a valvularfunnel-shaped opening ; this tube passes between the two pos-terior caecal appendages of the stomach, and terminates in asmall aperture (n), at the margin of the posterior disc. Thegangliated nervous chain (g) is uniform in its developmentthroughout the body, giving off nerves at

Note About Images