NERVOUS SYSTEM 



111 



TABLE 12— Concluded 



35 

 36 

 37 



38 

 39 

 40 

 41 

 42 

 43 

 44 

 45 

 46 

 47 

 48 

 49 

 50 



167 

 208 

 173 

 197 

 259 

 177 

 265 

 213 

 213 

 137 

 196 

 135 

 141 

 150 

 171 

 137 



189 

 203 

 194 

 201 

 214 

 195 

 216 

 203 

 204 

 177 

 200 

 179 

 179 

 182 

 192 

 178 



o s 



< tc 

 cs « 



O 6( 



1.80 



1. 



1.82 



1.86 



1.92 



1.83 



1.92 



1.86 



1.86 



1.74 



1.85 



1.75 



1.75 



1.76 



1.81 



1.75 



SOLUTIONS USED FOB 

 FIX.^TION 



Lang's fluid 



Lang's fluid 



Marina's fluid 



Marina's fluid 



Cor. sublimate 



Cor. sublimate 



Sublimate-formol . . 

 NaCl + sublimate. 



Tellyesniczky 



Tellyesniczky 



NaCl+ sublimate. 

 Sublimate-formol . . 



Cox (osmic) 



Cox (osmic) 



Cox (formol-acetic) 

 Cox (formol-acetic) 



P5 S 



- 7 



- 3 

 -29 

 -33 

 -23 

 -23 

 -14 

 -25 

 -12 

 -14 

 -19 

 -22 

 -12 

 + 4 

 -17 

 -13 



3. A 4 per cent solution of formaldehyde neutralized with Na2C03 

 produces a much greater amount of swelling in the brain of the rat 

 than does a solution that has a faintly acid reaction. 



4. A strong neutrahzed solution of formaldehyde causes a greater 

 percentage weight increase in the rat's brain than does a weak neutral- 

 ized solution. A reverse result is obtained when the solutions are not 

 neutralized. 



5. If rats' brains are subjected to the action of a solution of 

 formaldehyde that is kept at a constant temperature of 36°C., they 

 undergo a greater amount of swelling than is produced when the solution 

 is kept at a temperature of 8 to 11 °C. The maximum weight increase 

 in the brains is reached by the end of the first day in the former case, 

 and not until the third day in the latter case. 



6. When the conditions under which the solution acts are uni- 

 form, the maximum weight increase in rats' brains subjected to the 

 action of a 4 per cent solution of formaldehyde is attained in all cases 

 by the third day, and there is then a gradual decrease in weight. Brains 

 of very young animals tend to reach the maximum earlier than do those 

 of older animals. 



