16 INTRODUCTION TO CYTOLOGY 



biology.' The first clear expression of it is found in Virchow's Cellular Pathology, 

 published in 1858. It was not, however, until the period of Balfour, and through 

 the work of Fol, Van Beneden (chromosomes, 1883) Boveri, Hertwig, and 

 others, that the great importance of this conception began to be appreciated, 

 and came to be woven into the fundamental ideas of development.'' 



The Beginning of the Modern Period in Cytology. As Wilson (1900, 

 p. 6) points out, the great significance of the many facts brought to light 

 in the early days of cytology lies in the relation which they bear to the 

 Theory of Evolution and to the problems of heredity, though for many 

 years this was only vaguely realized. Darwin, aside from his Hypothesis 

 of Pangenesis, scarcely mentioned the theories of the cell; and not until 

 many years later was the cell investigated with reference to these matters. 

 Researches on the origin of the germ cells, nuclear division, and fertiliza- 

 tion, which brought the Cell Theory and the Theory of Evolution into 

 intimate association, began shortly after 1870 with the works of Schneider 

 (1873), Auerbach (1874), Fol (1875, etc.), Biitschli (1875, etc. ),O.Hertwig 

 (1875, etc.), van Beneden (1875, etc.), Strasburger (1875, etc.), Flemming 

 (1879, etc.), and Boveri (1887, etc.). These men laid the foundations for 

 the work which has followed; and their researches, greatly aided by the 

 development of new refinements in microtechnique, ushered in modern 

 cytology. A powerful stimulus to investigation was given when the 

 zoologists Hertwig, von Kolliker and Weismann, and the botanist Stras- 

 burger, concluded independently and almost simultaneously (1884-J885) 

 that the nucleus is the vehicle of heredity, an idea which Haeckel had put 

 forward as a speculation in 1866. The announcement of this conception 

 led to an even more intensive study of the nucleus and of its role in 

 heredity, a study which is now in progress, and which, more than any 

 other one thing, can be said to characterize the work of our modern period. 



Bibliography 1 



A, Works dealing wholly or in part with the history of cytology, and general works on 



the cell: 

 AGAR, W. E. 1920. Cytology, with Special Reference to the Metazoan Nucleus. 



London. 



BOVERI, TH. 1891. Befruchtung. Ergeb. d. Anat. u. Entw. 1 : 386-485. 

 BUCHNER, P. 1915. Prakticum der Zellenlehre. 1. 

 BURNETT, W. J. 1853. The cell; its physiology, pathology, and philosophy, as 



deduced from original investigations. Trans. Am. Med. Assn. 6. 

 CHUBB, G. C. 1910. Article on Cytology in Encycl. Brit., llth ed. 

 DELAGE, Y. 1895. La structure du protoplasme et les theories sur I'hereditc. 



Paris. 



DONCASTER, L. 1920. An Introduction to the Study of Cytology. London. 

 FLEMMING, W. 1882. Zellsubstanz, Kern und Kerntheilung. Leipzig. 



1981-1897. Referate iiber Zelle. Ergeb. d. Anat. u. Entw. 1-7. 

 GURWITSCH, A. 1904. Morphologie und Biologie der Zelle. Jena. 

 HAECKER, V. 1899. Praxis und Theorie der Zellen- und Befruchtungslehre. 

 HEIDENHAIN, M. 1907. Plasma und Zelle. Jena. 



