LABORATORY EXERCISES I 23 



(h) Draw both ventral and lateral views of a skull. Show the sutures 



and identify the bones, 

 (i) Draw lateral, dorsal and anterior views of a dorsal or lumbar 



vertebra to show centrum, neural arch, dorsal spine, transverse 



processes and articulating processes, 

 (j) Draw a cross section of bone from a prepared slide. Note the 



Haversian canals, the lamellae, the lacunar and canaliculi. 

 (k) In the leg of a frog from which the skin has been removed note 



how the fleshy mass is composed of distinct muscles. Note also 



the tendons and the relation of muscle to bone. Between the 



muscles may be found nerves and blood vessels. 

 (1) Study cross striped muscle fibres in a prepared slide, 

 (m) In a median longitudinal section of a dog fish (Galeus or 



Mustelus) study carefully the brain and spinal cord. Note also 



the vertebral column and compare the other organs of the 



body with those of lamprey as in f. 

 (n) In another specimen which has been dissected to show the 



cranial nerves and brain identify the following: 



1. Brain: Olfactory lobes, cerebrum, optic lobes, cerebellum, 

 medulla oblongata. 



2. Cranial nerves: I Olfactory, II Optic, III Oculomotor, IV 

 Trochlearis (slender), V Trigeminal, VI Abducens (slender), 

 VII Facial, VIII Auditory, IX Glossopharyngeal, X Vagus. 



3. Spinal cord and spinal nerves. 



(o) Draw dorsal and lateral views of the brain of a mammal showing 



cerebral hemispheres, cerebellum, and medulla, 

 (p) Slit the skin of a frog along the mid-dorsal line, lift the skin of 



one side and note the median dorsal cutaneous nerves passing 



out to the skin, 

 (q) With a lens search the inner surface of a piece of skin of a frog and 



observe the white nerves, the veins and the arteries, the three 



often running parallel, 

 (r) Study the digestive system of a frog or turtle. Note : oesophagus, 



stomach, small intestine, liver, gall bladder, pancreas, large 



intestine. Note also the mesentery and the spleen, 

 (s) Study as in r the digestive system of some mammal, 

 (t) On the surface of a tongue (mammal) find the circumvallate and 



fungiform papillae. If present note also the character of the 



glottis and epiglottis. 



