CELL SIZE AND METABOLIC ACTIVITY IX AMPHIBIA. 37 1 



tions are the result of differer^es in the aeration rate. This 

 factor could not be accurately controlled by the apparatus used. 

 However careful observation and comparison of the results of 

 over 250 aerations has convinced the writer that the variations 

 noted are not the result of differences in aeration rate. Main 

 result-^ were discarded in which there was good reason to believe 

 that an abnormally slow aeration had produced a low result. 

 Uaily temperature records of the room in which the experiments 

 were carried on were made, and these records show no fluctuations 

 which could possibly account for the daily variations found in the 

 results for individual animals. It is tentatively concluded that 

 ut are dealing with unexplained variations in the metabolism of 

 the animal. 



4. Se\ is re-pon-ible for some minor variations in the re-ults. 

 1 1 i- known that basal metabolism proceeds at a higher rate in 

 men than in women. The same appears also to be true of 

 Amphibia. If comparable weights be chosen, it is found that 

 Necturi female No. 4 is lower than male No. 7, and that female 

 Mo. N is lower than male No. 9. Rana fxilnstris female- Nbs. 

 j and 4 are lo\\er than male No. 3. 



5. I MMM-I- \\as responsible for some aberrant results in Ktuni 

 }>i/-ifns. S M ial of the animals (Nos. I, 3, 7 and 8) died of a 

 disease \\hich the writer has called "lymph a-dema." It is 

 accompanied by an accumulation of lymph, or water, in the 

 Miln maiieon- lymph sinuses, leading to a marked increase in 

 weight ami a swollen appearance. In the later stage-- this \\a_s 

 invariably ai "inpanied by capillary bursting in the skin and 

 muscles. < Mi autopsy the liver was spotted and the spleen en- 

 larged and crowded with blood. All the animals that died from 

 >uch <edcma -ho\\ed a sharp rise in carbon dioxide production 

 at the onset of the symptoms. This production remained high 

 until death in spite of the increased weight which would tend to 

 reduce the carbon dioxide per gram weight. For instance No. 3 

 had a rise from 0.1521 to 0.2427 at the onset of the disease, and 

 died with a production of 0.1798 mg. per gm. of weight in spite 

 of a j.s per cent, increase in weight. No. 6 died from a com- 

 plication of causes, which included a brain tumor connected with 

 the posterior choroid plexus on the right side, a fatty degenera- 

 tion which invoked the entire right kidney and part of the left. 



