54 PROTOZOOLOGY 



rod, composed of kinoplasm, on the surface of which are arranged 

 skeletal fibrils (Fig. 15). The contraction of the stalk is brought 

 about by the action of kinoplasm and walls, while elastic rods will 

 lead to extension of the stalk. Myonemes present in the ciliates aid 

 in the contraction of body, but those which occur in many Gre- 

 garinida aid apparently in locomotion, being arranged longitudi- 

 nally, transversely and probably spirally (Fig. 15,c). In certain Radio- 

 laria, such as Acanthometron elasticum (Fig. 195, c), etc., each axial 

 spine is connected with 10-30 myonemes (mj^ophrisks) originating 

 in the body surface. When these myonemes contract, the body vol- 

 ume is increased, thus in this case functioning as a hj^drostatic 

 organella. 



In Isotricha prostoma and I. intestinalis, Schuberg (1888) observed 

 that the nucleus is suspended by ectoplasmic fibrils and called the 

 apparatus karyophore. In some forms these fibrils are replaced by 

 ectoplasmic membranes as in Nydotherus ovalis (Zuluta; Kudo), 

 ten Kate (1927) studied fibrillar systems in Opalina, Nyctotherus, 

 Ichthyophthirius, Didinium, and Balantidium, and found that 

 there are numerous fibrils, each of which originates in a basal granule 

 of a cilium and takes a transverse or oblique course through the 

 endoplasm, ending in a basal granule located on the other side of 

 the body. He further noted that the cytopharynx and nucleus are 

 also connected with these fibrils, ten Kate suggested morphonemes 

 for them, since he believed that the majority were form-retaining 

 fibrils. 



The well-coordinated movement of cilia in the ciliate has long 

 been recognized, but it was Sharp (1914) who definitely showed that 

 this ciliary coordination is made possible by a certain fibrillar system 

 which he discovered in Epidinium (Diplodinium) ecaudatum (Fig. 

 16). Sharp recognized in this ciliate a complicated fibrillar system 

 connecting all the motor organellae of the cytostomal region, and 

 thinking that it was "probably nervous in function," as its size, ar- 

 rangement and location did not suggest supporting or contractile 

 function, he gave the name neuromotor apparatus to the whole 

 system. This apparatus consists of a central motor mass, the 

 motorium (which is stained red with Zenker fixation and modified 

 Mallory's connective tissue staining), located in the ectoplasm just 

 above the base of the left skeletal area, from which definite strands 

 radiate: namely, one to the roots of the dorsal membranellae (a 

 dorsal motor strand) ; one to the roots of the adoral membranellae 

 (a ventral motor strand); one to the cytopharynx (a circum-oeso- 

 phageal ring and oesophageal fibers); and several strands into the 



