Albert C. Eycleshymer 307 



tions of the fD^ril. If this interpretation be correct, we should find in 

 the muscle cell a process quite analogous to that found in many, indeed 

 most, cells of the organism — the building up and giving off of nuclear 

 material. This material may participate in the elaboration of the various 

 secretions, as is known to be the case in a great many gland cells, or may 

 give rise to more permanent products, such as the haemoglobin of the red 

 blood cell (Xecturus and Amblystoma), the yolk nuclei of the egg, the 

 Nissl bodies in the nerve cell, and, as I believe, the basophile portions 

 of the muscle fibrils. 



IV. Conclusion. 



The chief results of my studies can be stated in a few words. They 

 show that in the muscle cell of Xecturus nuclear differentiation is 

 scarcely less marked than cytoplasmic. They warrant the assumption 

 that nuclear material plays a most important part in cytoplasmic s}^- 

 theses. They suggest that cellular degeneration and regeneration are 

 accompanied by volumetric, structural and chemical changes in chro- 

 matin. Above all, they emphasize the importance of a more precise 

 study of nuclear changes during cytomorphosis. 



PARTIAL LIST OF REFERENCES. 



The writer has not attempted to compile the literature on the subject; this 

 has been done so thoroughly by a number of investigators that its repetition 

 here would be superfluous. The following list includes only those titles which 

 are not found in the bibliography given by Heidenhain, " Structur der con- 

 tractile Materie," Ergebn. d. Anat. u. Entwickelungsgesch., Wiesb., 1899, Bd. 

 VIII, pp. 1-111. 



Apathy, S., 92. — Contractile und leitende Primitivfibrillen. Mitth. a. d. zool. 

 Station zu Neapel, Leipz., 1892, Bd. IX. 



Bardeen, C. R., 00. — The development of the musculature of the body wall in 

 the pig, including its histogenesis and its relation to the myotomes 

 and to the skeletal and nervous apparatus: Johns Hopkins Hosp. 

 Rep., Baltimore, 1900, Vol. XI, pp. 367-399. Reprinted in Contribu- 

 tions to the Science of Medicine, dedicated to W. H. Welch, Baltimore, 

 1900, pp. 367-399. 



Carlier, E. W., gg. — Changes that occur in some cells of the newt's stomach 

 during digestion. La cellule, Louvain, 1899, T. XVI, pp. 403-464. 



Delage, Yves, g^. — La Structure du Protoplasma et les Theories sur I'heredite 

 et les grand Problemes de la Biologie Generale. Paris, 1895. 



Garnier, Charles, gg. — Contribution a I'etude de la structure et du functionne- 

 ment des cellules glandulaires sereuses. Du role de I'ergastoplasm 

 dans la secretion. These, Nancy, 1899. 



Gehuchten, a. van, 86. — Etude sur la structure intime de la cellule musculaire 

 striee. La cellule, Louvain, 1886, T. II, pp. 293-353. 



