THE PHILIPPINE 



Journal of Science 



d. ethnology, anthropology, and 

 General Biology 



Vol. V DECEMBER, 1910 No. 6 



EUPLOTES WORCESTERl SP. NOV.: 11.' DIVISION. 



By La WHENCE Edjionds Gkiffis.^ 



The literature on divii^ion in the family of the Euplotidie is surpris- 

 iugly limited, considering its wide distribution, the case with which 

 observations can be made vipon several of the species, the interesting 

 processes involved, and the number of competent naturalists who have 

 made observations on the group. The only important paper dealing with 

 tills subject is the excellent article of Wallengren upon the processes of 

 construction and resorption occurring during division in the H^'potricha; 

 Euplot(_'s harpa is tlie principal type of this study. AVallengren then 

 critically compares the accounts of Stein, Mobius, Maupa, and Schuberg 

 cimcerning Euplotes rharon, E. patclln, and E. harpa. All of the 

 accounts are ver}- incomplete and, like that of Wallengren himself, 

 are confined to the external changes. Wallengren has made a very care- 

 ful study of the formation of the new peristome and of the origin of the 

 new cirri during the division of Euploics harpa, and of the resorption 

 of the old set of cirri which are replaced liy the new ones formed. 

 Furtlier reference will be made to this article as my description of the 

 processes occurring in Euplotes worcesterl progresses. Unfortunately, 

 T was not able to secure the original article of Wallengren until after 

 my paper was ready for the press ; my observations upon the origin of the 

 peristome were therefore entirely independent. Since reading Wallen- 



^ Contribution from the Biological Laboratory, Bureau of Science, Manila, P. I. 

 - Associate professor of zoology in the University of the Philippines. 

 9945S 315 



