viii CYTOLOGY 



A glance through the pages of this book will show that it makes no 

 pretence to trace the historical development of the science, and conse- 

 quently the works selected for special reference are not always those 

 which contain the first, or even the most important, contribution to the 

 matter under discussion. In most cases they have been selected either 

 as giving a particularly clear account of it, or because they contain good 

 general discussions and literature lists which would be useful to the 

 student referring to them. 



Since the book is intended to give a summary of the more important 

 results of cytological research, it follows that the great majority of the 

 figures are taken from the original works of other authors scattered through 

 various scientific journals. They have in nearly every case been redrawn 

 for the purpose by Miss Helen L. Ness, often with the omission of details 

 not required for the purpose for which they are used. 



