626 



VERTBBEATED ANIMALS. 



Arrangement of Ihe Capillaries of the air-cells of 

 tile Human Lung. 



termination of each air-tube in man, is not less than 18,000; 

 and that the total number in the entire lungs is six hundred 



439. The following list of the parts of the bodies of Verte- 



brata, of which Injected pre- 

 parations are most interesting 

 as Microscopic objects, may 

 be of service to those who 

 may be inclined to apply 

 themselves to their produc- 

 tion. Alimentary Canal; 

 Stomach, showing the orifices 

 of the gastric follicles, and 

 the rudimentary villi near the 

 pylorus ; Small Intestine, 

 showing the villi and the 

 orifices of the follicles of 

 Lieberkiihn, and at its lower 

 part the Peyerian glands ; 

 Large Intestine, showing the 

 various glandular toWicles i—Mesjnratori/ Organs; Lungs of 

 Mammals, Birds, and Reptiles ; Gills and Swimming-bladder of 

 Fish: — Gflandular Organs; Liver, Gall-bladder, Kidney, Paro- 

 tid: — Generative Organs; Oviduct of Bird and Frog; Mamma- 

 lian Placenta ; Uterine and Fcetal Cotyledons of Ruminants : — 

 Organs of Sense; Iris, Choroid, and Ciliary processes of Eye, 

 Pupillary Membrane of foetus; Papillae of Tongue; Mucous 

 Membrane of Nose; Papillae of Skin of finger: — Tegumcntary 

 Organs ; Skin of dififerent parts, hairy and smooth, with vertical 

 sections showing the vessels of the Hair-follicles, Sebaceous 

 glands, and Papillse; Matrix of nails, hoofs, &c. : — Tissues; 

 Fibrous, Muscular, Adipose, Sheath of Tendon. 



440. Development. — The study of the Embryological develop- 

 ment of Vertebrated animals has been pursued of late years 

 with great zeal and success by the assistance of the Microscope; 

 but as this is a department of inquiry which needs for its suc- 

 cessful pursuit a thoroughly scientific culture, and is only likely 

 to be taken up by a professed Physiologist, no good purpose 

 seems likely to be served by here giving such an imperfect out- 

 line of the process, as could alone be introduced into a work 

 like the present; and the reader who may desire information 

 upon it, will find no difllculty in obtaining this through systema- 

 tic treatises on Physiology.' 



' The Author takes the liberty of referring to his " Principles of Comparative Physio- 

 losry," 4th Ed. chap, xi, as containing a general view of the vi^hole subject, with refer- 

 ences to the principal sources of more detailed information. 



