194: Universify of California Piihlications in Zoologif [Vol 16 



new names "lokomotorische-generative und idiogenerative" chro- 

 matin. 



In the latest exposition of his views Hartmann (1911) has modi- 

 fied his earlier ideas on the general prevalence of the binuelear condi- 

 tion and limits it to those organisms which possess a second "nucleus" 

 which arises by an actual division of the "Hauptkern." "Von einer 

 eigentlichen Doppelkernigkeit dagegen kann nur dann gesprochen 

 werden, wenn durch eine polare Teilung des individualisierten Cen- 

 triols, sei sie homopol oder heteropol, zwei distinkte Keruindividuen 

 gebildet werden." All the forms in which he considers this to actu- 

 ally take place he includes in the order Binucleata, as follows: Her- 

 petomonas, Crithidia, Trypanosoma, Trypanoplasma, Prowazekia, 

 Leishmania, Halteridia, Haemogregarinida, Piroplasmida and Plas- 

 modiida. 



The work of Werbitzki (1910) in proving that the "kinetonucleus" 

 of the trypanosomes is not composed of nuclear chromatin, by show- 

 ing that it may be dissolved out by chemicals which have no action 

 on the nucleus, has shown the need of further investigations before 

 claiming for any extra-nuclear ehromidial body, because of its stain- 

 ing reactions, the specific properties of nuclear chromatin. 



II. Critical Discussion of the Binucleat.a. 



The followers of Schaudinn have upheld the views and theories re- 

 garding binuclearity which he put forth and have made constant and 

 repeated endeavors to confirm them, with the result, it must be con- 

 fessed, of sometimes seeming to rely on his authority rather than 

 critically to discuss the alternative possibilities raised by the actual 

 conditions and new discoveries. This has resulted in the seeming con- 

 firmation of some views ^^hich, in the hands of other less partisan ob- 

 servers, have proven to be errors of interpretation or observation. A 

 notable instance of such error is the work of Schaudinn (1904) him- 

 self on the parasites of the little owl {Athene noctuae). In spite of 

 the strong doubts cast upon the correctness of these observations by 

 the results of the work of Novy and McNeal (1906), the Sergents 

 (1906), Woodcock (1910), and Minehin and Woodcock (1911), as well 

 as others, this work has been used by Hartmann as one of the founda- 

 tion stones for his later modification of the binuelear theory, and the 

 creation of the order Binucleata. 



In this, as in the earlier theory, the starting-point is the nuclear 

 nature of the "kinetonucleus" or the parabasal body, a word formed 



