1916] Swezy: Kiiu'foinirlciis <if Flai/ellotcs 231 



established. His own work affords the strongest evidence vet brought 

 forth to disprove this theory. 



These results also strike at the root of Hartmann's whole binuclear 

 theory, namely, at the idea tliat the parabasal body is composed of 

 "lokomotoi'iseh-generative" und "idio-generative" chromatin. It is 

 conceivable that we may be here dealing with chromatin in a different 

 physiological condition, which may, therefore, be acted upon by sub- 

 stances which do not aft'ect the nuclear chromatin. This, however, 

 will not agree with Hartmann's contention that these bodies are com- 

 posed of the same kinds of material. The same may be said of any 

 other structure of the cell body, and proves nothing in regard to its 

 nuclear value. 



The effects of the loss of this structure on the trypanosonies thus 

 treated is shown only by a slightly diminished virulence. The struc- 

 ture, division, activity, etc., all appear to be absolutely normal. It 

 cannot be maintained that this disproves the idea of the function of 

 the parabasal body as part of the motor apparatus. The motor func- 

 tions were iindoubtedly possessed wholly by the blepharoplast origin- 

 ally, as they still are in all free-living flagellates and a few parasitic 

 forms. It is therefore quite probable that with the secondary loss of 

 this organelle, the parabasal body, the blepharoplast assumes all of 

 its original functions again. That the loss of one organ or part of it 

 may be compensated by the remaining part and its functions carT'ied 

 on, is of such frequent occurrence among the Metazoa that we would 

 naturally expect to find some evidence of the same ability among the 

 Protozoa. 



Kudicke (1911) has pointed out the fact that in normal trypano- 

 somes in laboratory cultures individuals are frequently observed with- 

 out parabasal bodies. The loss of the nucleus under the same condi- 

 tions has been observed by Hartmann and Prowazek (1907) in Leish- 

 mania. Flu (1908) and Berliner (1909) described the same abnorm- 

 ality in Crithidia and Herpctomonas. It cannot be emphasized too 

 freely in this connection that laboratory cultures, under the best pos- 

 sible conditions, present an abnormal, or it may be even pathogenic, 

 environment to the organisms which normally live in the body of an- 

 other animal. Under such circumstances the production of abnormal 

 and degenerating forms are of frequent occurrence. These abnormali- 

 ties disappear when the flagellates are replaced in their normal habi- 

 tat ; hence their development proves nothing except the presence of ab- 

 normal or pathological conditions for the protozoans. 



