i8o 



THE SPOROZOA 



processes may be wanting entirely. The surface of the cuticle is 

 not smooth, however, but has a delicately ribbed or fluted 

 structure, producing fine striations which run in a meridional 

 direction from pole to pole. As a rule there are no openings or 



visible pores of any kind in 

 the cuticle, but, according 

 ^ to Siedlecki, a pore exists 



at the anterior end of Lan- 

 ^ : kesteria ascidiae, from which 

 is protruded a minute 

 pseudopodium-like process 

 which serves for the 

 secondary attachment of 

 the trophozoite to an intes- 

 tinal cell of the host, and 

 -<& pores are stated to exist in 

 the longitudinal furrows of 

 the cuticle, as described 

 below. 



The ectoplasm is a 

 clear, hyaline layer of 

 tougher protoplasm which 

 in the motionless forms 

 shows no special differen- 

 tiation. But in most 

 Gregarines, correlated with 

 the power of active move- 



Trophozoites of Didymophyts. a,D.paradoxa,8tein ment, the deeper layer of 



(par. Geotrupes stercorarius), two associated sporonts ; tV. or>tr>rlaem r>nntain<5 a 



in the satellite the protomerite has disappeared. 6, ttle ectoplasm contains a 



D. gigantea, Stein (par. Oryctes nasicornis), cephalont. system of contractile fibrils, 

 P. primite ; S satellite ; ep, epimerite ; mi. proto- -, . > j 



merite ; de, deutomerite ; n, nucleus. marking Ott a deeper 



myocyte from a more super- 

 ficial sarcocyte layer of the ectoplasm (Fig. 26, m.f, sc). The sarcocyte 

 is prolonged inwards to form the septum separating protomerite 

 and deutomerite, when this division is found. The fibrils of the 

 myocyte (Figg. 26, m.f, and 27) run in a more or less circular 

 direction, with numerous oblique junctions and anastomoses, so 

 that the system as a whole is more or less net-like. 



The movements of Gregarines are often very active, though 

 some forms appear perfectly motionless. Two kinds of move- 

 ments are commonly seen. In the first place, the body manifests 

 contractions of various kinds, without changing its place as a 

 whole. It may bend and straighten again, or may exhibit ring-like 

 constrictions which pass down the body in a manner resembling 

 peristaltic movement. The latter is a very characteristic form of 

 activity, and resembles greatly the " metabolic " form-changes seen 



FlG 25 



