THE FURTHER AND FINAL RESEARCHES OF JOSEPH 



JACKSON LISTER UPON THE REPRODUCTIVE 



PROCESSES OF POLYSTOMELLA CRISPA 



(LINNE) 



(An Unpublished Paper Completed and Edited from His Note-Books) 



By EDWARD HERON-ALLEN, F. R. S. 



(With Se\'en Plates) 



INTRODUCTORY NOTE 



For over 30 years Lister's work upon the reproductive processes 

 of the megalospheric form of Polystoinella crispa (Linn.) by means 

 of flagelHspores has been famihar to protozoologists, and especially 

 to students, both in text-books and in the lectures of university pro- 

 fessors, and it recurs incessantly in examination papers. For over 

 30 years it has been well known that his equally, if not more, impor- 

 tant work on the reproductive processes of the microspheric form by 

 what may not improperly be called viviparity had been completed, 

 but with the exception of the short postscript to his paper published 

 in 1895 it has not been available to protozoologists. The reason for 

 this is difficult to fathom for anyone who did not know him inti- 

 mately. We know that his nervous sensibility was such as to reach 

 at times a pathological condition, and he could never be persuaded to 

 publish anything that he took it into his head to keep to himself. 

 I suppose that, so far as the Foraminifera were concerned, I was his 

 most intimate friend and fellow-worker, but, though we frequently 

 visited each other and continually corresponded, he never showed 

 me any of these preparations, photographs, or lantern slides. 



I esteemed it therefore as a great privilege that I was allowed, after 

 his death, to sort and arrange the whole of his microscopical materials 

 and preparations, and the papers and note-books relating to them, 

 and having found the whole of his material, his slides and his own 

 unpublished paper upon it, I was permitted by the late INIrs. Lister, 

 herself a noteworthy zoologist, to give to the world of science the 

 information that it had been awaiting for 30 years. 



When the last and the youngest of the men that he taught have 

 died ; when the problems attaching to Astroclera have been solved ; 



Smithsonian Miscellaneous Collections, Vol. 82, No, 9 



