492 0. H. MAirnx. 



the straud of tlie karyosorae which liad connected the two 

 troplionuclei, and whicli has not yet been withdi-awn. 



Finally, the kinetonucleus becomes shortened and denser, 

 the last i^emains of the karyosome strand ai-e absorbed, and 

 the animal elongates and regains its normal aspect. 



Conclusions. 



I liavo tlionght that it might be of some interest to com]);ire 

 shortly the above account of division of Try panoplasma 

 congeri with that given ])y previous workers for other 

 species of Try panoplasma. As far as I am aware, tlie 

 only accounts of division in a trypanoplasma liitherto pub- 

 lished are those by Keysselitz, in his paper, " Generations- und 

 Wirtswechsel im Try panoplasm a borreli" (1906), and by 

 Friedrich, in his paper, "Uber Bau und Naturgeschichte der 

 Trypanoplasma helicis" (1909). Keysselitz gives on page 

 28 of his ]):iper five figures of dividing active forms from the 

 blood of thetish, i.e. figs. 12, 14,22,23,24. From these 

 figures it would appear that the process of division in 

 T ry pano})lasin a congeri shows some diffei'ence frum 

 that of Trypanoplasma borreli, though, as his series of 

 division seems far from complete, it is quite possible that 

 these differences may be more apparent than real. 



(1) As regards the behaviour of the Hagella, Keysselitz 

 seems inclined to believe that one of the products of the 

 division keeps the old flagelhi, and that the other at a com- 

 pai'atively Inte stage grows out new Hagella. 



(2) In T. borreli, according to Keysselitz, the tropho- 

 nucleus divides, showing an internal division centre derived 

 from the karyosome and eight chromosomes, at a stage at 

 whicli there is no sign of division in the Hagella, blepharo- 

 plast, or cell body. 



(3) The kinetonucleus is said to divide transversely. 



The difficult feature in this account of division seems to 

 me the extraordinary amount of variability in the time factor 

 for all these processes ; in fact, Keysselitz himself states on 

 page 31 : "Den Verlauf der Teilung habe ich bisher in alien 



