CHROMIDIA AND THE BINUCLEARITY HYPOTHESES. 319 
many, many more facts and unbiassed observations before 
we can hope to unravel the tangled skein of cytological 
problems of which the foregoing form but a small part. 
But in the study of the complex simplicity of the Protista we 
have already found a beginning. 
CAMBRIDGE, 
August, 1908. 
LITERATURE. 
[This list does not claim to be complete, or to contain every memoir in 
which chromidia and binuclearity are mentioned. It consists of the 
more important works upon which the foregoing pages are founded. | 
02. Ancel, P.—* Histogénése et structure de la glande hermaphrodite 
dHelix pomatia,” ‘ Arch. Biol.,’ xix. 
06. Awerinzew, S.—‘ Die Stisswasser Rhizopoden,” ‘Tray. Soc. Nat.,’ 
St. Petersburg, xxxvi (2). 
07. * Beitrage zur Kenntnis der Flagellaten,” ‘ Zool. Anz.,’ xxxi. 
08. “Studien tiber parasitische Protozoen, I-VII,” ‘Trav. Soe. 
Nat., St. Petersburg. 
*04. Bluntschli, H.— Beobachtungen am Ovarialei der Monascidie 
Cynthia microsomus,” ‘Morph. Jahrb.,’ xxxii. 
06 Bott, K.—* Uber die Fortpflanzung von Pelomyxa palustris,” 
‘ Arch. Protistenk.,’ viii. 
00. Boveri, T.—* Zellenstudien, IV; Uber die Natur der Centro- 
somen,” Jena. 
02. Brandt. K.—‘“ Beitrage zur Kenntnis der Colliden (I u. II)” 
‘Arch. Protistenk.,’ i. 
“Beitrage zur Kenntnis der Colliden (III),” ‘Arch. 
Protistenk.,’ vi. 
05. 
‘91. Biitschli, O.—‘ Uber die sogenannten Centralkérper der Zelle 
und ihre Bedeutung,” ‘ Verh. naturhist. med. Ver. Heidelberg 
Nee. av: 
98. Calkins, G. N.—* The Phylogenetic Significance of Certain Pro- 
tozoan Nuclei,” ‘ Ann. Acad. Sci.,” New York, xi. 
* Mitosis in Noctiluca miliaris and its bearing on the 
Nuclear Relations of the Protozoa and Metazoa,”’ ‘Journ. 
Morphol.,’ xv. 
°99. 
, 
