i6 
MAMMALIAN ANATOMY 
or by cutting with a sharp, thin knife the well-hardened bodies 
of embryos sufficiently advanced to show the typical form and 
arrangement of parts ( e.g., guinea-pig embryos measuring from 
7 to io cm. in length). These sections should include not only 
transverse sections through both the thoracic and the abdominal 
regions but also a median sagittal section to show the longitudinal 
extent and relationships of the parts studied. All these prepara¬ 
tions should be studied under water or 70% alcohol, and, in case 
embryos are used, they should be studied under a dissecting 
microscope. 
Study for the general plan of the body, especially the location 
and boundaries of the neural and coelomic cavities, and the 
relation of the serous membranes of the latter to the walls of the 
cavity and to the contained organs, with the identification of 
the latter. Note also, especially in the transverse sections, the dis¬ 
position of the muscle masses with relation to the skeleton, and 
compare these sections with certain familiar cuts of meat (e.g., 
loin and rib chops). 
Draw a transverse section through the body of the dogfish, and 
a median sagittal section through a mammalian body, adult or 
embryonic. If time permits draw also a good typical transverse 
section through the mammalian thoracic region and a similar section 
through the mammalian abdominal region. 
