50 THE MICROSCOPE. Apr., 



a single book in English at his command that he could 

 turn to for any definite information. Ehrenberg's work 

 is in German, and while the illustrations are most valua- 

 ble, the text gives no descriptions of genera or species but 

 is confined to notes on the geology of the subject and to 

 references to the different localities. Mrs. Bury's atlas is 

 merely a collection of plates without any text. Haeck- 

 el's Monograph on the Radiolaria (1862) is also in Grerman. 



It is true his later magnificent work on the Radiolaria 

 is in English but has not been at the command of the stu- 

 dent owing to the price, about forty dollars, and few 

 would have known where to find a copy even for occa- 

 sional consultation. There is a copy in the Astor Li- 

 brary and I believe there is another in the Library of 

 Columbia College, but beyond these two I know of no 

 others in public libraries in and around New York. Un- 

 less I am very much mistaken it is not in the Brooklyn 

 Library or even in that of the Philadelphia Academy. 

 Most amateurs have recourse simply to such a work as 

 that of Carpenter on the Microscope and nothing could 

 show more strikingly the dearth of information available 

 on the subject than that work. For the Radiolaria are 

 disposed of in about five pages of text of which only two 

 are given to the classification and they afford almost no 

 help. I am speaking of the sixth edition which is the 

 one in most general use. But the seventh is little better. 



Contrast the elaborate treatment of the Foraminifera 

 which takes up fifty pages or of the Diatoms to which 

 forty pages are devoted. In fact it was this dearth of 

 available information, which led me to write the series 

 of articles on the subject which have appeared during 

 the last three years in the Journal. But even when the 

 information is given there is another difficulty, namely 

 the large number of terms necessary in description owing 

 to the astonishing variety of form presented by the Radi- 

 olaria. So that even with the key before him the stu- 



