i88 



Journal of Comparative Neurology. 



control frog. When the solids and water in the cord were to 

 be determined, the cords were dried at about 85°C., complete 

 drying being accomplished in about 24 hours. In making a 

 comparison of the results, the average weight of "the standard 

 millimeter of cord" was the datum used in each case. 



In presenting our results, we shall give averages together 

 with the records for the limiting cases, but the series of individ- 

 ual observations is omitted. The various tables have been con- 

 structed in the following way. There are given first the date 

 of observation, then the limits of the room temperature and of 

 the jar containing the absorbing frog. Finally, a statement of 

 the general conditions to which the absorbing frog was subjected. 

 Beyond this it will be probably most advantageous to explain 

 Table I in some detail, and then comment on the subsequent 

 tables in so far as they depart from the form there used. 



Experimental Results. 



In the first instance we sought to determine the increase 

 in weight of the absorbing cord under ordinary laboratory con- 

 ditions. Table I is based on the comparison of eleven pairs of 

 frogs. In the Table they are presented in three groups, being 

 divided according to body weight. The observations were 

 made between July 20th, and July 30th, on frogs caught within 

 three days and kept in a dark tank through which tap water 

 was constantly flowing. There were elevations in the tank so 

 that the Irogs could be in or out of the water at will. 



Within in the jar containing the absorbing frog the temper- 

 ature ranged from 20°-22°C. The absorbing frog was not dis- 

 sected until 24 hours after death. 



TABLE I. 



Percentage gain in "Standard mil- 

 limeter" of the spinal cord of the 



Body Weight in grams. absorbing frogs. 



Extremes Average Average Extremes 



