318 UR. T. GOODEY ON 



produced. The chromatin now becomes re-arranged in grannies 

 of varying size and shape, as shown in figs. 41-44. 



During the later stages of nuclear division, the anterior sur- 

 face of the body becomes much drawn out and flattened. A. 

 depression now appears on this sxn-face of the body and gradually 

 travels backwards, and at the same time, in some cases, the 

 protoplast extends laterally (fig. 44). In other cases the body 

 becomes triangular in outline, and large vacuoles appear towards 

 the centre of the body and, by rupturing, assist in the pro- 

 duction of the daughter-organisms (figs. 42 & 43). Division of 

 the body is thus longitudinal in direction. Fig. 45 shows two 

 newly-formed organisms which ha,ve recently sepaiated, their 

 drawn-out tail-ends overlapping slightly. 



(c) Systematic Position. 



The possession of four flagella places my organism undoubtedly 

 in the genus Tetrcmiitus Perty, and though this to--day is a very 

 mixed assemblage of forms, comprising, as it does, the free-living 

 organisms described by Perty and by Klebs ('92), and also the 

 pai-asitic forms Tetramitus {Macro stoma) mesnili (Wenyon, '10 a) 

 and Tetramitus [Macrostoma) catdleryi (Alexeieff, '11 a), there is 

 no reason why I should create a fresh genus for its reception. 

 As, however, I have been unable to discover any description or 

 figures of any free-living member of the genus which fits my 

 organism, I have decided to make a new species of it, namely, 

 spiralis. 



(3) Spiron-ema multiciliatum Klebs. (PI. III. figs. 46-48.) 

 (a) Structure. 



This highly intei-esting organism occurred in one culture made 

 from Broad balk 1865 soil. It appeared both on the surface and 

 at the bottom of the culture. My attention was first attracted 

 to it by reason of its great length and its peculiar method of 

 locomiOtion. It moved slowly in a very hesitating jerky manner 

 for the most part, but would suddenly exhibit rapid and violent 

 spiral twists commencing at its anterior end and travelling down 

 the body, at which times it was propelled at a reasonably fast 

 pace. It was obvious that the organellse causing the slow jerky 

 motion were situated at or towards the anterior end, though 

 they could not be distinguished under a low power of the micro- 

 scope. Towards the posterior end a contractile vacuole could be 

 seen in diastole and systole. 



I was able to obtain film preparations which, when fixed and 

 stained, revealed the structure of the organism very clearly. 

 The body is extremely long in comparison with the width, and 

 is dorso-ventrally flattened. It measures anything from 20-50 fj. 

 in length, and averages about 4 ^ in width. The middle region 

 is generally the widest part of the body. The anterior end is 

 either rounded or has a lateral knob-like portion on either side. 



