62 University of California Publications in Zoology [Vol. 16 



8. Gill-like outgrowths can be moved in any desired direction by 

 changing the position of a hot pin applied to the outer surface of 

 the cover-slip. 



9. Connective tissue was kept in a healthy growing condition for 

 forty-one days, when it was accidently killed. 



This work was carried on in the laboratory of Professor S. J. 

 Holmes, whose criticisms and suggestions are sincerely appreciated. 



Transmitted September 10, 1915. 



IMPORTANT REFERENCES 



C.4RREL, A. 



1912a. Technique for cultivating a large quantity of tissue. Jour. Exp. Med., 



15, 393-396. 

 1912b. On the permanent life of tissues outside of the organism. Jour. 



Exp. Med., 15, 516-528, pis. 75, 76. 

 C.^RRELL, A. and Burrows, M. T. 



1911a. Cultivation of tissues in vitro and its technique. Jour. Exp. Med., 



13, 387-395, pis. 38-46. 

 1911b. An addition to the technique of the cultivation of tissues in vitro. 



Jour. Exp. Med., 14, 244-247, pis. 25-27. 

 Ebeuxg, a. II. 



1913. The permanent life of connective tissue outside of the organism. 



Jour. Exp. Med., 17, 273-285, pis. 53, 54. 

 Harrison, R. G. 



1910. The outgrowth of the nerve fiber as a mode of protoplasmic move- 

 ment. Jour. Exp. Zool., 9, 787-848, pis. 1-3, 32 figures in text. 



1912. The cultivation of tissues in extraneous media as a method of morpho- 

 genetic study. Anat. Rec, 6, 181-193. 



1914. The reaction of embryonic cells to soliil structures. Jour. Ex]i. Zool., 



17, 521-544, 14 figures in text. 

 Holmes, S. J. 



1913a. Observations on isolated living pigment cells from the larvae of 



amphibians. Univ. Calif. Publ. Zool., 11, 143-154, pis. 5-6. 

 1913b. The behavior of eetodermic epithelium of tadpoles when cultivated in 



plasma. Univ. Calif. Publ. Zool., 11, 15.5-172, pis. 7-8. 

 1914a. The cultivation of tissues from the frog. Science, n.s., 39, 107-108. 

 1914b. A culture medium for tissues of amphibians. Science, n.s., 40, 32-33. 

 1914c. The behavior of the epidermis of amphibians when cultivated outside 



of the body. Jour. Exp. Zool., 17, 281-295, pi. 1. 



SUXDWALL, .J. 



1912. Tissue proliferation in plasma media. Bull. Hyg. Lab. U. S. Pub. 

 Health Mar. Hosp. Serv., 81, l-r)4, pis. [17]. 



