PROTOZOA WITHOUT MOTILE ORGANS 57 



any other of the unicellular animals must be regarded as provisional 

 only and comprising numerous heterogeneous groups of organisms 

 which can be more accurately classified only after the full life histories 

 are made out. Some of these groups are obviously related to the 

 mastigophora through the blood-dwelling flagellates, and others are 

 equally related to the sarcodina. Two divisions only, the gregarinida 

 and the coccidiidia. may be accepted as sufficiently definite to constitute 

 an acceptable division of the protozoa. At the present time, Schau- 

 clinn's grouping into telosporidia and neosporidia cannot be bettered, 

 although evidence is accumulating to show that the latter group is 

 entirely artificial. 



SUBPHYLUM SPOROZOA. Parasitic protozoa without motile 

 organs, but capable of moving from place to place by structural mod- 

 fications of one kind or other. Reproduction either simple or multiple, 

 but mainly by spore formation, which is either asexual (schizogony) 

 or sexual (sporogony). 



The following classification of sporozoa is based upon Labbe's 

 "sporozoa," and upon "sporozoa" in Lankester's Treatise on Zoology, 

 Part I, Introduction and Protozoa. Second fascicle, with additions 

 and changes necessary for the present work and to bring the classifi- 

 cation up to date. 



Suhphylurn SPOROZOA. 



Class I. TELOSPORIDIA, Srliaiidinn. Sporozoa in which sporulation ends the 

 life of the individual. 



Order 1. Gregarinida. Coelozoic telosporidia reproducing usually by spore forma- 

 tion alone, and after the fertilizing union of but slightly different gametes. 



Suborder 1. SCHIZOGREGARIX.K. ( Jrcgarines reproducing by division or by 

 multiple budding in addition to spore formation. 



This interesting group, which is continually being added to by various obser- 

 vers, was until finite recently represented by only those supposedly ameboid 

 forms known as the Amcbosporidia. The investigations begun by Leger 

 and carried on by Leger, Dubosq, Dogiel, Brasil, and others of recent date 

 have shown that the supposed ameboid processes are actually unchangeable, 

 serving more as attaching organs and for the purpose of absorbing food 

 than for the purposes of locomotion. 



There is no question that these forms are gregarines, and from the very 

 characteristic types included here there is some hope of ultimately getting 

 light upon the closer relationships of the entire group of sporozoa to other 

 groups of protozoa. 



Genus 1. Schizocystis, Leger, 1900. Type species S. gregarinoides, Leger, from 

 the intestine of larva of Ceratopogen sp. The trophozoites are somewhat 

 similar to Monocystis, but cliffer in reproducing by the formation of a group 

 of internal buds, which, as merozoites, leave the parent cell and grow into 

 new trophozoites; these finally couple up, fertilization and sporulation result, 

 and octozoic spores are finally formed, as in Monocystis (Fig. 76). 



Genus 2. Ophryocystis, A. Sch., 1 SS4. Many species are known, most of which are 

 parasites hi tlie Malpighian tubules of beetles. The organisms have char- 

 acteristic pseudopodia-like processes for purposes of attachment, and the 

 trophozoites reproduce by simple division or by multiple division. Sporula- 

 tion ultimately takes place, the process differing in different cases (Fig. 801. 



