ALCOHOLS AND FATIGUE PROCESSES 
173 
muscle, both as to stimulation or sensitization and inhibition or 
anaesthetic effects. Strong concentrations in general give remark- 
ably uniform modifications in phases of contraction, especially in 
producing immediate contracture which merges without interrup- 
tion into irreversible secondary contracture. Certain weak solu- 
tions in general are markedly stimulating as is evidenced by an 
initial and somewhat prolonged relaxation phase followed by a 
reversible contracture phase which is very pronounced. Certain 
predictable differences were obtained in concentrations between 
the two extremes. 
The evidence, presented would seem to indicate that when they 
are undergoing the process of fatigue muscles are qualitatively 
susceptible to differences in concentration of the medium with 
which they are surrounded. This implies that an intimate rela- 
tion exists between the physical state of the muscular envelop 
(plasma-membrane) and the changing physiological conditions 
within. 
REFERENCES 
1. From the Physiological Laboratory, Dept, of Zoology and Entomol- 
ogy, Iowa State College, Ames, Iowa. 
2. Baldwin, F. M., Biol. Bull., Vol. 38, pp. 123-140, 1920. 
3. Carlson, A. J., Am. Journ. Physiol., Vol. 17, p. 182, 1906. 
4. Tashiro and Adams, Internal. Zeitsch. f. Physik-Chem. Biol., Vol. 1, 
p. 450. 
5. Lee, F. S., Am. Journ. Physiol., Vol. 18, p. 267, 1907. 
6. Stockard, C. R., Am. Journ. Anat., Vol. 10, p. 369, 1910. 
7. McClendon, Am. Journ. Physiol., Vol. 29, p. 289, 1912. 
8. Lillie, R: S., Biol. Bull., Vol. 30, No. S, 1916. 
9. Pratt, F. H., Am. Journ. Physiol., Vol. 44, No. 4, p 530, 1917. 
Physiological Laboratories, 
Iowa State College 
