HO THE AMERICAN MONTHLY [Apiil 



of that work to enlist in its ranks. No other stipulation 

 is made. It is a band of workers interested in each other's 

 ])ursuits and willing- to g-ive and take whatever aid their 

 union can supply. They do not set themselves on a pin- 

 nacle as experts and specialists but claim to be merely a 

 small company working- for the g^eneral good and well 

 aware that the humblest observer may be able to add 

 knowledge and experience that will be of value to all. The 

 yearly subscription to the A. M. S. is two dollars with an 

 entrance fee of three dollars. In return for that the mem- 

 bers receive free a copy of the published papers of the 

 Society. 



Quekett Microscopical Club. Mr. W. Stokes gave a 

 descripti()nof some easily-made monochromatic light filters 

 for microscopical purposes. The subject was further dis- 

 cussed by Mr. Nelson, Mr. Rheinberg-, and others. Mr. 

 T. Rosseter read a paper "Experimental Infection of the 

 Domestic Duck with Cysticerci or Larval Tapeworms." 

 Specimens and drawing-s were showm, by the author, of Dic- 

 ranota_niia coronula ind Cysticercus coronula, Drepanidot- 

 ajnia gracilis- and Cysticercus gracilis, D. tenuirostris and 

 Cysticercus tenuirostris, in which cases he had proved by 

 direct experiment that the g-iven Cysticerci were really 

 the larval forms of the tapeworms specified, and the mat- 

 ter was now no long-er one of mere surmise from the iden- 

 tity of the booklets, &c. The secretary said Mr. Rosseter 

 appeared to be the sole investig-ator of the life history of 

 this interesting group of bird parasites in this country. 



Mr. Nelson exhibited a new triplet mag-nifier he had 

 computed with a working di&tance of 8-10 in., a new ach- 

 romatic and aplanatic bull's-eye, and read a paper on the 

 secondary structure of the diatom, Kittonia elaborata. 



In consequence of April 16th being- Good Frida}', the 

 next ordinary meeting- will be held on F^riday, May 21st. 



The Collsg-eof Physicians and Surg-eons, of Chicag-o, has 

 recently become the Medical School of the University of 

 Illinois, 



