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suspensory part. Lower Jaw-- Distinct bones in the frog; one mass in the dog. Otic Capsule-- Position as specified. One centre of ossification in the frog forming pro-otic; several fuse together and form periotic of the dog. There is no bulla and no external ear in the frog. Palate-- In the frog the posterior nares open into the front of the mouth. In the dog the maxillae and palatines send plates down and in (the palatine plates) to cut off a nasal passage from the rest of the buccal chamber, and carry the posterior nares back to the pharynx, thus cutting the vomers off from the mouth roof. The pterygoids in the dog are much reduced, and do not reach back to the suspensorium. The frog has no lachrymal bone. -Syllabus Of Practical Work_ We would impress upon the student at the outset the importance of some preliminary reading before dissection is undertaken. No one would dream of attempting to explore a deserted city without some previous study of maps and guide-books, but we find again and again students undertaking to explore the complicated anatomy of a vertebrated animal without the slightest, or only the slightest, preparatory reading. This is entirely a mistake. A student should be familiar with the nomenclature of the structures he contemplates examining, he should have some idea of their mutual relations and functions, or his attention will inevitably be diverted by the difficulty of new names and physiological questionings to the neglect of his dissection, and that careful observation of form and mutual position which is the essential object of dissection. On the other hand, it is equally necessary-- perhaps more so-- to warn students against the bookish fallacy, and to assure them of the absolute impossibility of realizing biological facts from reading alone. Practical work can alone confirm and complete the knowledge to which the text-book is the guide. In scientific teaching it may sometimes be convenient for the thought to precede the thing, but until the thing has been dealt with the knowledge gained is an unsatisfactory and unstable possession. For such dissection as the subject-matter of this book requires, the following appliances will be needed:-- (a) Two or three scalpels of various sizes. (b) Scissors, which must taper gradually, have straight blades, and be pointed at
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