VI 



PROTOPLASM 



" Entmischung " and " Ausbreitung," applied to the peculiar 

 physical phenomena described fully on p. 15 and p. 62 et 

 seq. respectively. Not being able to find English equiva- 

 lents for these words I applied to Lord Eayleigh, Sec. R S., 

 for advice, and with his kind help I have coined the word 

 desolution for " Entmischung," while " Ausbreitung " I have 

 rendered at his suggestion by the word extension or super- 

 ficial extension. There is no need for me to explain these 

 terms here, as that is done in the text at the places 

 indicated. 



Protoplasm is conceived of in this work as having the 

 structure of a froth or foam in which minute droplets of a 

 watery liquid take the place of air in the bubbles of an 

 ordinary foam. Such a structure is termed by the author 

 " Wabenstructur," i.e. honeycomb structure ; the separate 

 vesicles, bubbles, or droplets of the foam are termed 

 " Waben," i.e. cells of a honeycomb. The latter word has 

 been rendered throughout by the term alveolus, and the 

 structure is generally termed alveolar. The most super- 

 ficial layer of radially directed alveoli, which gives the ap- 

 pearance of a striated border, has been termed by the 

 author the "alveolar layer" ("Alveolarschicht") par excellence. 

 In order to avoid confusion this has been rendered in many 

 places marginal alveolar layer, in other places simply 

 alveolar layer. 



The plan has been followed of printing the book in two 

 types, in order that the student may be able to obtain first 

 of all a general idea of its contents, without entering into 

 details, by reading the portions printed in the larger type 

 consecutively. 



Finally, it is my pleasant duty to express my thanks 

 for the assistance I have received in preparing this transla- 

 tion. Without Professor Piay Lankester's kind help the 

 work would never have been undertaken. To the Author 



