2 '2 (J mOTOZOA. 



22. In conjugation portions of the niicroniicleus are exchanged 

 anil accomplish impregnation. The macronucleus degenerates and 

 is replaced by part of tho fecundated micronucleus. 



22. The classification of the Ciliata is based on the structure 

 a]ul arrangement of the cilia. 



23. The Ilolotridiu have similar cilia over the whole body. 

 The Heterotriclia have besides the total ciliation stronger cilia in 

 the neighborhood of the mouth (adoral ciliary spiral). The Peri- 

 trirlia have only adoral ciliation. The Ilypotriclia have, on the 

 ventral surface, the ciliary spiral and rows of cilia and coalesced 

 cilia. The Sudoria have cilia oiily in the young, later they 

 become attached and feed through suctorial tentacles. 



24. Spoeozoa are jjarasitie Protozoa, usually without organs 

 of locomotion or mouth. They take no solid food, but live by 

 osmosis on tissue fluids. In reproduction the encysted animals 

 produce spores (apparently always beginning with fecundation and 

 accompanied by a change of host). The spores divide again into 

 sporozoites. Besides, multiplication without change of host (auto- 

 infection) can occur. 



25. Tlie Grefjariinda are temporary or permanent parasites in 

 cells. (Spores = ^jseudonavicellaj, sporozoite = falciform embryo). 

 (_'ucridia\ Hamosporida (cause of malaria, parasitic in blood 

 corpuscles). 



3G. The )Sarcosj)Orida (liainey's or Miescher's corpuscles of 

 mammalian muscles) and JIj/xosjKiridii (psorospenn capsules of 

 fishes, psorosperm = spore) live in tissues or hollow organs. 



APPENDIX. 



According to ihe evolution theory one should expect forms between the 

 Protozoa and Mctazoa. Tlie Catallacta — spheres of ciliated cells which iu 

 reproduction break up into single cells — have been described as such. 



WSWm-^ 



iillWlilw 



Fio. 160.— Section of luilt of Tiichoiilax uiihareiis. (After Schulze.) 

 Peculiar many-celled animals whose position in the system is diflicult to 

 decide are, furtlier, Trifhniilux adha-rena, iSaliiieUa sah'e, tho Ortuo- 

 NEOTIDA and tho DiCYEMiDA, 7'n'c/iopla.r (iig. 100) is discoid and consists 

 of twoepitlielial-liko cell layers se|)aratcd by gelatinous tissue. The Ortho- 



