130 



SECRETION. 



25. Digestive enzyme. Sections through a mammalian pancreas at intervals 

 after a meal. Note the gradual evacuation of the granules of secretion from the cells 

 into the lumen of the gland. 





26. Venom. Specimen of a scorpion to show the sting and the position of the 

 poison gland. 



27. Venom of a toad exuding from the poison glands. 



