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INDUCED BREEDING 



point just behind the tympanic nnembrane, then across the skull to the other 

 side of the head, and sever the skull from the body. Invert the jawless head 

 and push aside the oral skin, thereby exposing the cross formed by the para- 

 sphenoidal and transverse bones. Insert the sharp point of smaller scissors 

 into the cranial cavity, ventral to the exposed medulla, and cut through the 

 floor of the cranium on either side of the brain in an anterior direction. 

 Avoid injury to the brain tissue because in doing so the pituitary may be lost. 

 The two parallel cuts should extend well anterior to the transverse bone. 

 With forceps, deflect this flap of bone in a forward direction, thereby expos- 

 ing the brain. The anterior pituitary gland should be seen lying just posterior 

 to the optic chiasma and will appear as a pinkish, kidney-shaped body sur- 

 rounded to some extent by white endolymphatic tissue. Occasionally the 



ANTERIOR PITUITARY GLAND OF FROG 



Diagram showing position of the pituitary gland of the 

 frog as it might be seen through the parasphenoidal bone, 

 lying just beneath the brain. 



A - Anterior lobe of the pituitary gland. 

 Note its more posterior position. 



B - Pars intermidia and pars nervosa. 



E - Eye ball as seen through oral skin. 



L - Endolymphatic tissue adherent to the pituitary. 



O - Exoccipital bone. 



P - Parasphenoidal bone. 



R - Retractor bulbi muscle. The attachment of 

 this muscle to the parasphenoidal bone must 

 be partially removed. 



S - Levator anguli scapuli muscle. 



V - First vertebra. 



gland will remain adherent to the floor of the brain case and will have been 

 deflected forward with the bone. Remove the gland by grasping the white 

 endolymphatic tissue surrounding it, using sharp forceps. This endolymph- 

 atic tissue has no known endocrine, function. Place the gland in 1 to 2 cc. of 

 water in a small slender. In a similar way proceed with the removal of as 

 many glands as are necessary. Pituitary donors need not be freshly caught 

 animals but they must be sexually mature and in a pre-breeding condition. 



