GROWTH OF THE CEREBRAL CORTEX 



519 



TABLE 3 



Showing the average age, body weight, body and tail lengths and brain weight grouped 

 by brain weight of the albino rats used in this study for sagittal and frontal 

 sections, accompanied by the calculated standard age, body weight, body and tail 

 lengths corresponding to the given brain weights 



1 Pregnant one omitted. 



- Rigor mortis. 



' All calculated by formulas for sexes combined. 



As a result, Bouin's fluid (picric acid solution in water at room 

 temperature, saturated, 75 vol., formalin 25 vol. and glacial 

 acetic acid 5 vol.) was selected as most suitable for the present 

 work. When the rat brain is fixed in this fli»id for 24 hours, 

 the shape and the weight of the total brain suffer but little, if 

 any, change, as the result of the fixation. The other fluids com- 

 monly used for fixation either swell or shrink the brain very 

 noticeably (King, '10). On comparing the sections obtained 

 from brains fixed in other fluids with those fixed in Bouin's fluid, 



