April 5, 1918] 



SCIENCE 



347 



is found to furnish a possible explanation of 

 the controlled sex ratios. 



Not only can the sex of pigeons be changed 

 but it can also be accentuated. The females 

 hatched from the second egg of the clutch, 

 laid in the autumn by overworked birds, are 

 more pronounced females than the normal fe- 

 males of the species. This is evidenced by the 

 persistence of a right ovary in such birds. In 

 normal female pigeons the right ovary has 

 completely degenerated in the week-old squab. 



The literature reviewed gives evidence of a 

 relation between rate of metabolism and sex 

 in a great variety of animals, varying from 

 worms to man. With sex viewed as an expres- 

 sion of differentiated metabolic activity, its 

 independent origin in diverse groups of or- 

 ganisms ceases to be a stumbling block, being 

 no more remarkable than that the same color 

 should have originated independently in dif- 

 ferent groups. The work reported is confined 

 to the animal kingdom and it should be of in- 

 terest to determine whether in dioecious 

 plants there is a corresponding differentiation 

 in the rate of metabolic change. 



Dr. Riddle's work would seem to call for 

 discussion by those students of genetics who 

 place the distribution of the chromosome in a 

 causal relation to sex, since his results di- 

 rectly challenge this interpretation. It is 

 shown that in some cases at least sex is deter- 

 mined before the segregation of the chromo- 

 somes, a fact which would seem to make 

 chromosome number a characteristic rather 

 than a cause of sex. 



Furthermore, the challenge extends to all 

 Mendelians, for if " one hereditary character 

 (sex) is modifiable, is of a fluid, quantitative, 

 reversible nature," surely the alternative na- 

 ture and stability of other characters come in 

 question. 



It is worthy of note that all three investiga- 

 tors, though working in widely separated 

 fields and approaching the problem of evolu- 

 tion from very different angles, conclude that 

 evolutionary change is, in effect at least, a 

 gradual process that is not beyond the power 

 of man to man influence. 



G. N. Collins 



SPECIAL ARTICLES 



THE ROLE OF CATALASE IN ACIDOSIS 



If an inorganic acid, such as hydrochloric, 

 be administered to an animal, it is neutralized 

 by the alkalies of the blood and tissues; if an 

 organic acid be administered, it is oxidized, 

 unless the oxidative processes of the animal 

 are defective, as in diabetes, in which case the 

 organic acids are neutralized, as are the in- 

 organic. This neutralization of acids leads 

 to a depletion of the " alkaline reserves " of the 

 body, which produces the condition known as 

 acidosis. By the term acidosis is meant the 

 impoverishment of the tissues and blood in 

 alkalies. In very severe cases of diabetes, 

 the animal is not able to burn sugar and can 

 burn fat and protein only as far as ;8-oxy- 

 butyric and diacetic acids and acetone, hence 

 the tissues of the diabetic would become acid 

 in reaction were it not for the fact that the 

 acids formed in this disease are neutralized by 

 the alkalies of the tissue. Since this neutral- 

 ization leads to a depletion of the "alkaline 

 reserves " of the body in severe cases of dia- 

 betes and since acidity of the tissues is incom- 

 patible with life, the animal dies. From the 

 foregoing it is readily understood how the in- 

 travenous infusions of sodium bicarbonate are 

 helpful in overcoming the coma of diabetes. 

 Besides diabetes, it is known that acidosis oc- 

 curs in '• surgical shock," in anesthesia, and 

 in starvation. It is also known that in these 

 conditions oxidation is decreased and that the 

 accumulation of the resulting incompletely 

 oxidized substances, acid in nature, are respon- 

 sible for the acidosis. The present investiga- 

 tion was carried out in an attempt to find 

 an explanation for the decreased oxidation 

 with resulting acidosis in the conditions men- 

 tioned. 



Diabetes. — Pancreatic diabetes was pro- 

 duced in dogs by extirpating the pancreas. 

 Sugar appeared in the urine a few hours after 

 the operations. About two weeks later, when 

 tlie animals were in a moribund condition, they 

 were killed and the blood vessels were washed 

 free of blood by the use of large quantities of 

 0.9 per cent, sodium chloride, as was indicated 



