150 SAKYO KANDA. 



positively heliotropic by chemicals. 1 Since then, Holmes. 2 

 Minkiewicz, 3 Drzewina, 4 Jackson, 5 Moore, 6 Ewald, 7 and others 

 have shown many examples of the reversibility of heliotropism 

 in animals by chemicals, temperature, etc. R. S. Lillie, 8 Mast, 9 

 and the writer 10 have also observed the reversing effect of chemi- 

 cals on the positive heliotropism of Arenicola larvae. These 

 observations, however, were rather incidental and not extensive, 



In this paper, the writer shows quantitatively that the normal 

 heliotropism of Arenicola larvae can be reversed by various 

 chemicals and by higher or lower temperatures than normal. 

 And it will be seen that those chemicals which produce artificial 

 parthenogenesis in sea-urchin and other eggs have also a re- 

 versing effect on the heliotropism of Arenicola larvae. This 

 parallelism between the reversal of the normal heliotropism of 

 the larvae and artificial parthenogenseis is striking as regards all 

 chemicals used by the writer except inorganic acids. 



The experimental work was done partly under the direction of 

 Professor R. S. Lillie in the physiological department of the 

 Marine Biological Laboratory at Woods Hole, Mass., U. S. A., 

 during the summer of 1914. Publication has been delayed 

 chiefly on account of the writer's return to Japan. The writer 

 wishes here to acknowledge his indebtedness to Prof. Ralph 

 S. Lillie and Prof. Elias P. Lyon for their valuable suggestions 

 and criticism of the work and manuscript. His thanks are due 

 also to Director Frank R. Lillie, who gave him the use of a re- 

 search room in the laboratory. 



II. MATERIAL AND METHODS. 



The larvae of the marine annelid, Arenicola cristata, were used 

 for this work. The procedure of obtaining the larvae was exactly 



1 Loeb, Jacques, Univ. of Calif. Pub., Physiol., Vol. 2, p. i, 1904. 



2 Holmes, Samuel J., Jour. Comp. Neur. and Psychol., Vol. 15, 305, 1905. 



3 Minkiewicz, R., Arch. d. Zool. Exp. et Gen., t. 7, p. 37, 1907. 



4 Drzewina, Anna, C. R. Soc. Biol., Vol. 71, 555. 



6 Jackson, H. H. T., Jour. Comp. Neur. and Psychol., Vol. 20, p. 259, 1910. 



6 Moore, A. R., Science, N. S., Vol. 38, p. 131. 



7 Ewald, Wolfgang F., Jour. Exp. Zool., Vol. 13, p. 591, 1912. 



8 Lillie, Ralph S., Am. Jour. Physiol., Vol. 24, p. 14, 1909. 



9 Mast, Samuel O., "Light and the Behavior of Organisms, xi + 410 p., 1911. 



10 Kanda, Sakyo, Am. Jour. Physiol., Vol. 35, p. 162, 1914. 



