Identifier: introductiontozo00dave Title: Introduction to zoology; a guide to the study of animals, for the use of secondary schools; Year: 1900 (1900s) Authors: Davenport, Charles Benedict, 1866-1944 Davenport, Gertrude Anna Crotty, 1866- Subjects: Zoology Publisher: New York, Macmillan company London, Macmillian and co., ltd. Contributing Library: MBLWHOI Library Digitizing Sponsor: MBLWHOI LibraryView Book Page: Book Viewer About This Book: Catalog Entry View All Images: All Images From BookClick here to view book online to see this illustration in context in a browseable online version of this book.Text Appearing Before Image: FIG. 299. —Choloepus, the unau or two-toed sloth. After Vogt and Specht. such as the dolphins, the toothed whales (Fig. 300),and the toothless or whalebone whales. The largest ofthese whales - - the Greenland whale - - reaches an ex-treme length of twenty-two to twenty-four metres, and a 1 cetus, whale. 2 From a native name. 3 The relation to Cetacea is not close. THE MOUSE AND ITS ALLIES 325 weight of over 100,000 kilogrammes. It is, indeed, thelargest living animal. Although whales in general arepartly adapted to an aquatic life, they still retain theessential mammalian qualities. They breathe air whichpasses to the lungs and is expelled again through thenostrils, which are placed high up on the head. The blowing of the whale is the forcible expiration ofmoisture-laden air, which becomes visible by condensation,Text Appearing After Image: FIG. 300. — Oca, the killer whale. After True. just as our own breath does on a cold day. The youngare doubtless born in the water, but the breeding habitsare poorly known. The various Cetacea have diversefeeding habits. All are predaceous. The toothed whalesfeed on larger animals, the whalebone whales on floatingfish, Crustacea, medusae, and squids ; their whalebone is,indeed, merely a strainer to let the water pass out of themouth while the solid masses are retained. The order Ungulata1 includes a large number of animals, 1 unyula, hoof. 326 ZOOLOGY almost all of which are closely related. In the true ungu-lates there are never more than four functional toes; butin the subgroup of Subungulata, containing the elephantsand certain small animals allied to the coney ofScripture, there are typically five. Of the true ungulates,we distinguish the even-toed and the odd-toed, which wemay consider further.Note About ImagesPlease note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.