AtJTHOR's ABSTRACT OF THIS PAPER ISSUED 

 BY THE BIBI.IOORAPHTC 8EUVICE, JUNE 30 



FACTORS INFLUENCING THE BEHAVIOR OF THE 

 BRAIN OF THE ALBINO RAT IN MULLER'S 



FLUID 



JAMES STUART PLANT 

 Neurological Laboratory of The Wistar Institute of Anatomy and Biology 



The brain of the albino rat, placed for a period in Miiller's 

 fluid, exhibits a typical change. In the course of time it not 

 onl}^ hardens, but also markedly increases in weight. There is a 

 rapid increase to a maximum in about one week's time, after 

 which there is a slow, steady loss until the seventy-five day 

 weighing, at which time the brain weighs 20 to 30 per cent more 

 than when fresh. It was thought that changes in this typical 

 curve might be induced in the brains of rats previously anes- 

 thetized for prolonged periods, and it was hoped that this cri- 

 terion would be more delicate than the microscopic or analytic 

 tests which had, so far, failed to demonstrate a change. The 

 work was done at The Wistar Institute of Anatomy during the 

 academic year 1913-1914. 



PLAN 



The main question of the effect of the anesthetic on the typ- 

 ical curve remains unanswered. From the start, however, it 

 was recognized that various factors influenced the reaction of 

 'control' brains to Miiller's fluid — factors which are inherent in 

 the material. It is these factors and their influence on the reac- 

 tion with which the present paper deals. 



PROCEDURE 



The brains studied belonged to 'stock' albino rats. The 

 animals were killed with ether and the brains quickly removed 

 with every care not to damage them. They were immediately 

 weighed and then suspended in 50 cc. of Miiller's fluid. The 



411 



