PART II. CHARACTERS AND DIAGNOSIS 75 



be traced from the commencing division of the nuclei to the 

 completion of longitudinal splitting of the flagellate. 



In this process the whole complicated system of sucking disc 

 with its related flagella is reproduced on the dorsum of the flagel- 

 late, but the tracing of the details of this process is a very difficult 

 matter which is only to be compared with the difficulty of following 

 the division in the encysted forms. When the whole flagellar 

 apparatus has been duplicated the subsequent division can be 

 readily followed, and is so clearly illustrated in the figures that 

 little description is necessary. Apparently the flagellate splits 

 longitudinally, the fissure passing in between the sucking discs 

 from before backwards. Before this takes place the complete 

 apparatus of the new flagellate is reproduced. The final stage 

 is seen where two flagellates are attached only by the tapering 

 posterior extremities. 



Division of the flagellates had evidently been taking place with 

 rapidity, for there was a very great variation in the size of those 

 present in the film. There were present flagellates showing every 

 gradation in size, from large forms measuring 17 by 10 microns to 

 smaller forms measuring 10 by 6 microns. In some parts of the film 

 streaks or patches of mucus occurred which were packed with 

 these small forms, while in other places the mucus contained 

 only large forms. The small flagellates had the same structure as 

 the larger ones, except that the sucking disc appeared to occupy a 

 greater portion of visible surface of the flagellate. There was no 

 tendency for these small forms to take on the octomitus structure, 

 so that there is no reason to assume, as some have done, that the 

 lamblia is a later stage in the development of octomitus. An 

 octomitus of man has recently been described by Chalmers and 

 Petskola in the Sudan. Kofoid and Christiansen have recently 

 described binary and multiple fission in the lamblia of mice (Proc. 

 Nat. Acad. Sci., November, 1915). 



As regards the cysts of lamblia we have little new information 

 to offer. In certain cases where the cysts had apparently been 

 formed only recently, judging by the thinness of the wall and 

 the fact that they had not yet assumed the perfectly ovoid form 

 so characteristic of the mature cyst, the single lamblia within 

 could still be seen moving its posterior extremity slightly from side 

 to side, while the central pair of flagella were undulating slowly as 

 one often sees them in lamblia which have ceased to swim about 

 actively. At a later stage the cyst becomes more accurately ovoid 

 and the wall tougher, while the single lamblia within may or may 



