406 ADVANCED PHYSIOLOGY 



and a drop of it should be examined under a microscope and compared 

 with milk. 



CHAPTER VIII 



Page 115. Cover the bulb end of a thistle tube with some membrane 

 like the lining of an egg shell or a piece of goldbeater's skin, tying it tightly. 

 Fill the bulb with solution of glucose, holding the bulb in dish* of water 

 while doing so to avoid breaking the membrane, which is very thin. Then 

 lower bulb into the water till glucose and external water show the same 

 level. Fasten the tube in this position ; the water will pass into the glucose 

 solution through the membrane, till glucose level is much the highest. 

 This occurs against the force of gravity, under no compulsion except that 

 of osmotic pressure. 



Page 120. The lacteal branches of the lymphatic system which arise 

 in the walls of the intestine may be plainly shown in the mesentery of a 

 cat or dog, if the animal is chloroformed about three hours after it has 

 eaten freely of fatty meat and milk. On opening the abdomen imme- 

 diately after death, the mesentery holding the intestine will be seen filled 

 with numerous tiny ducts full of white, fatty emulsion. 



CHAPTER IX 



Page 123. The plasma and corpuscles in blood can be shown by put- 

 ting a drop of fresh blood from a prick in the tip of the finger on a glass 

 slide, with a little 0.6% solution of common salt. It is not possible to 

 demonstrate the platelets except by special methods. Frog's blood is 

 also easily obtained. For permanent mounts of the blood see address 

 list of dealers. 



Page 125. 1. Defibrinated blood may be procured from a butcher, 

 by catching blood directly from some animal and stirring it immediately, 

 thus removing the fibrin as it forms. Blood so treated will not clot and 

 will keep for some time. Put some in a large test tube, and by means of 

 a glass tube opening into the bottom of the test tube run oxygen gas 

 through the blood. The bubbles which will be thus formed will be of 

 bright red color (oxyhaemoglobin) . For methods of making this gas, 

 see Appendix, " Formulae and Methods." 



2. The blood of a guinea pig, rat, or dog is best for showing oxyhaemoglo- 

 bin crystals. It is not so readily shown in human blood. The amount 

 of ether used should be only a fraction of that of the blood. If blood 

 is merely mounted in water and allowed to stand some time, crystals 

 form to some extent. 



