66 Connective Tissue Corpuscles. 



In some places masses of small cells will be found 

 deeply stained, these are germinating cells. 



Other serous membranes should be prepared by the 

 silver process, the centrum tendineum of the diaphragm 

 makes a very good preparation, showing the groups of 

 germinating cells, and the difference in shape of the 

 endothelium on each surface. 



The lymphatic capillaries will also be seen by the 

 different shape of the endothelium, giving them the ap- 

 pearance of trabeculse running through the membrane. 



A silvered preparation of the septum cisternae lym- 

 phaticae magnae should be made. 



Eemove the viscera from a recently killed frog, and a 

 large lymph sac will be found on each side of the spinal 

 column behind the stomach, the septum separates each 

 sac from the peritoneal cavity. It may be stained in 

 situ by pouring a little i per cent, solution of nitrate 

 of silver over it and allowing it to remain a few minutes, 

 or the septum may be carefully removed and placed in 

 silver solution. The septum will show the germinating 

 cells round the opening of the stomata. In all cases 

 where preparations of serous membrane are to be made, 

 the animal should be bled first. 



CONNECTIVE TISSUE COEPUSCLES. 



Make a gold preparation of Tadpole's tale. 



This will show the connective tissue corpuscles very 

 well with their branched processes. Pigment cells are 

 also numerous. Several of these preparations should 

 be made, as they show a great many different struc- 

 tures. 



