58 APPENDIX 



this with 95 parts distilled water. The body cavity should be 

 opened, a little to one side of the mid-line, to insure good preser- 

 vation of the viscera. 



Injected specimens may be prepared by injecting the arteries 

 through the truncus arteriosus (single injection), the hepatoportal 

 veins through the abdominal vein (double injection), and the re- 

 maining veins through the postcava (triple injection). The most 

 useful mass is prepared with cornstarch as follows: 



Cornstarch 4 parts by volume 



Chloral hydrate, 2% aqueous sol... 4 " 



Alcohol 95% 1 " 



Color and glycerine (equal parts) . . 1 " 



Mix and stir, strain through cheesecloth. 

 For colors use vermilion for arteries, insoluble Prussian blue for 

 hepatoportal vein, chrome yellow for postcava. 



Skeletons are prepared by boiling in the following soap solution : 



Soap 75 grams 



Potassium nitrate 12 " 



Ammonia 150 cc. 



Distilled water . : 2000 ce. 



Heat the water before adding the other ingredients. Use diluted, 

 one part of the mixture to three parts of water. 



To decalcify the skull before dissecting the brain use the follow- 

 ing mixture: 



Alcohol, 95% 1 part by volume 



Nitric acid, 10%; sol 1 " 



For the preparation of the slides called for, it wall be necessary 

 to consult the works on microscopic technique mentioned in the 

 Introduction. The blood smears may be stained with any of the 

 regular blood stains, although haematoxylin and eosin give prep- 

 arations quite adequate for class use. The sections may be pre- 

 pared by making use of sublimate-acetic for fixation, paraffin em- 

 bedding, Delafield's haematoxylin and eosin as stains, and balsam 

 for the mounting medium. For the sections of skin and intestine, 

 the writer recommends Bouin's fixing fluid, and his own modifica- 

 tion of Cajal's fuchsin and picro-indigo-carmine.'' This gives a 



* Vertebrate Embryology, page 283. 



