230 University of California Publications in Zoology [Vol. 16 



III. Nuclear Value Not Established by Evidence 



Undoubtedly the most important piece of work bearing on the 

 question of the nuclear value of the parabasal body is that of Werbitzki 

 (1910), who was able to produce a strain of trypanosomes lacking 

 these organelles. He treated infected animals with orthochinoid sub- 

 stances and found that under their influence the parabasal bodies of 

 the trypanosomes disappeared. In this way, by successive passages 

 six to ten times through mice treated with oxazin, a strain of trypano- 

 somes was obtained in which every individual was devoid of a para- 

 basal body. This strain remained constant in its subsequent passages 

 through untreated mice. 



Kudieke (1911ff) confirmed this work of Werbitzki. He did not 

 find it possible, however, to obtain a strain (19116) which would re- 

 generate the parabasal body, either by treatment with a drug, or by 

 transplantation into other animals as Werbitzki claims to have done. 



Laveran and Roudsky (1911) found that when oxazin and acridine 

 were injected into an infected animal the parabasal body of the try- 

 panosomes were stained pink or violet with the dye. This could be 

 observed in the living forms in a drop of blood from a treated mouse. 

 In the actively motile organisms the parabasal body began to dwindle 

 in size and finally disappeared. Various experiments showed that 

 these substances have a specific action on the parabasal body. The 

 suggestion has been made that its disappeai'ance is brought about by 

 auto-oxidation in the living animal, and the results seem to support 

 this view. 



This change has been found to occur in eight species of trypano- 

 somes: Trypanosoma briicei, evansi, soitdanense, gambicnse, dimor- 

 phon, pecornm, congolense, and lewisi. 



The total lack of action of the chemical on other parts of the cell, 

 particularly on the nucleus and blepharoplast, affords the strongest 

 possible evidence for the view that the component chemical sub- 

 stances of the parabasal body differ from those of the nucleus and 

 blepharoplast. It follows that the nuclear value of the parabasal 

 body, in thus lacking what has always been considered the essential 

 part of the nucleus, the nuclear chromatin, is absolutely disproved, so 

 far as its composition is concerned. 



Curiously enough Werbitzki (1910) begins his account of the re- 

 sults of his work along this line with the statement that the nuclear 

 character of the blepharoplast, as he calls the parabasal body, is fully 



