OBSERVATIONS ON TEYPANOPLASMA CONGERI. 491 



spindle to the longitudinal axis of the animal's body seems in 

 these early stages to be rather variable, but in the later 

 stages the long axis of the spindle seems always to be 

 arranged in direction transverse to the animal's orio-inal 

 longitudinal axis. The kinetonucleus now becomes very much 

 enlarged, and gradually (PI. 21, figs. 4-7) pushes out aposterior 

 limb, which comes to lie at right angles across the dumb-bell- 

 shaped trophouucleus. This relation seems very characteristic 

 of this stage of division, which is a very common one on these 

 films. It is ratlier interesting to note that the stages of 

 division up to this poiut in the films from this particular 

 conger are very common, the latter stages being comparatively 

 rare. As these films were taken from various points all over 

 the surface of the stomach, this would seem to point either to 

 a cyclical epidemic of division in this parasite or (a view 

 which seems to me rather more improbable) to an extremely 

 short duration for the later as compared with the earlier 

 stages of division. Tlie basal granules have now moved some 

 distance apart, and as the animal shortens aiid thickens the 

 membranes and flagella become shifted round till in the later 

 stages they pass down the opposite sides of the body. The 

 trophouucleus now is completely dumb-bell shaped, the 

 handle of the dumb-bell being formed by the strand connect- 

 ing the two karyosomes. In its early stages the dividing 

 trophonucleus has presented a very superficial resemblance, in 

 outline, at any rate, to the mitotic spindles found in the 

 metazoan cell, but in the succeeding stages, in which the new 

 ti'oplionuclei have become definitely rounded, and their con- 

 nection is limited to the bar joining the two karyosomes, tin's 

 resemblance is completely lost. In PI. 21, fig. 8, a late stage of 

 division is figured in which the two products of division are 

 still connected with each other by a narrowing band of proto- 

 plasm, through which, even at this stage, the kinetonucleiand 

 trophonuclei are still connected. In PI. 21, fig. 9, a form is 

 shown which has evidently just divided. It is characterised 

 firstly by its small size and rounded shape, secondly by the 

 length of the kinetonucleus, and thirdly by the remains of 



