1919] Kofoid-Siccci/: TriclKDiijuipha cam pdiiiila 47 



a more slender body, its width varying from 40 to 60/x. In shape 

 T. campanula differs but little from T. agilis, the latter having a 

 somewhat broader transdiameter anteriorly with a noticeable con- 

 striction near the middle of the body or slightly anterior to it. This 

 constriction is entirely absent in T. campanula. Its divergence from 

 T. hertwigi is still more pronounced, varying greatlj' in proportions 

 from any of the three distinct forms which Hartmann (1910) has 

 described under that name, being more slender anteriorly and broader 

 posteriorh'. 



Neuromotor System 



Included in tliis system is the entire set of fibers concerned in 

 movement of all parts of the body, both in the ectoplasm and the 

 endoplasm, the external coat of cilia, the three zones of flagella, and 

 the centroblepharoplast from which the other fibrils radiate, take 

 their origin, or with which thej' have some more or less direct con- 

 nection. In view of its manj- elements, their diversification into 

 various groups, and their structural coordination we apply the con- 

 ception of an organ system to their complex and designate it as tlie 

 neuromotor system. 



This system consists of two distinct parts, lying respectively in tJie 

 ectoplasm and endoplasm, and differing in their staining reactions 

 and in their relationships to the process of mitosis. The first part is 

 composed of the flagella, their basal granules and connections, the 

 anastomosing sheet of oblique fibers, the centroblepharoplast and 

 paradesmose. It appears to be more highly specialized as eonductile 

 organelles, although the flagella may be sensory and are certainly 

 contractile. This part of the system shares in mitosis, forms the polar 

 centrosomes, the structures radiating therefrom, and the paradesmose. 

 These organs lie in or project from the ectoplasm. The other part 

 consists of two antagonistic sets of fibers, the outer circular and 

 inner longitudinal myonemes. These lie against if not in the endo- 

 plasm, and take no direct part in mitosis. Their connections with 

 the centroblepharoplast are problematical. They are primarily con- 

 tractile. 



The use of the term neuromotor to designate the system is based 

 on morphological grounds and observations on the behavior of the 

 animal. It responds to stimuli, contracts, and moves as it might be 

 expected to do with such a structurally coordinated mechanism. It 

 must, however, be evident that the distinction between strictly neural 



