A RECONNAISSANCE OF THE RELATION BETWEEN DESICCATION AND CARBON DIOXIDE PRODUCTION IN ANIMALS

¹ HULL ZOÖLOGICAL LABORATORY, THE UNIVERSITY OF CHICAGO AND THE BIOLOGICAL LABORATORY OF THE UNIVERSITY OF ARIZONA

1. Desiccation is followed by marked changes in the physiological states of certain animals.

2. Agriolimax campestris Binney, Plethodon glutinosus Green, Acris gryllus Le Conte, and larvæ of Tenebrio molitor Linn show a definite, positive, correlation between desiccation and carbon dioxide production.

3. The above-named animals show a gradual increase in carbon dioxide production when desiccated to less than one half of the possible vital limit. Continued desiccation is followed by a decrease in carbon dioxide production, which falls below normal before the vital limit is reached.

4. The larvæ of Alypia octomaculata Fabricius show a decrease in carbon dioxide production in all stages of desiccation.

5. Xerophilous animals give up water more slowly and in proportion to water losses are more stimulated by dry air than hygrophilous animals.

6. Water starvation increases the depression of metabolic activity caused by food starvation.

7. Extremely dry air is a protoplasmic irritant.