BRE Saale. 
EN 
740 LIFE HISTORIES OF THE PROTOZOA. 
of these arms elongates, and separating forms a perfect Gregarina. | 
Soon afterwards the other arm elongates, absorbs the moner-like 
mass and also becomes a perfect Gregarina. This elongated stage 
is called a Pseudofilaria (Fig. 131, G). No nucleus has yet ap- 
peared. In the next stage (Fig. 131, H, n, nucleus) the body is 
shorter and broader, and the nucleus appears, while a number of 6 | 
granules collect at one end, indicating a head. After this the 
body shortens a little more (I, J), and then attains the elongated, 
worm-like form of the adult Gregarina (K). Van Beneden thus 
sums up the phases of growth :— eS 
1. The Moner phase. : 
2. The generating Cytode phase. 
3. The Pseudo-filaria phase. 
4. The Protoplast * (adult Gregarina). Mae 
5. The encysted Gregarina. Se 
6. The sporogony phase (producing zoospores). A 
It seems evident that the mode of development of the Gregarina l 
in part corresponds quite closely with the mode of growth of the : 
Moners ; for example, it becomes encysted, îi. e., sexually mature, 
produces zoospores (pscudonavicella), and from these zoospores 
issues the y oung or larval form of the Gregarina. These zoospores 
abound in damp places and are devoured by insects and worms: 
After they are swallowed the shells burst and the Ameaba-like 
young are set free in the body of their host. 
It will be seen that there is here a total absence of sexual repro 
duction. The Moner-stage arises by self-division of the content 
of the cyst, a process analogous to the segmentation of the yolk 
of eggs; and the Psendofilariz arise by self-division of the young 
in the Moner-stage, i. e., by a budding process. . 
LITERATURE. 
_ Dufour. Note sur la Grégarine. (Annales des Sciences Aaaa l xii. 
Siebold. Bei iträge zur Geschichte wirbelloser Thier 1813.) E 
Stein. Ueber die Natur der Gregarinen. (Mullers Archiv fiir A DE Zeite 
Ee Belirle atr Eonarois nioleres Thiere- (Siebold und Köll 
ouronnés de pPAcadđémie E — 
1828.) - 
849.) 
Paonia Evolution des Grégarines. (Mémoires c 
e Brux 
E. Van Beneden. On a i Naw sent of Gregarina to pe called Gregarina 9 
— (Quart. Journ. Microscopical Sc 187 pacad: 
——— Recherches sur i Pkectation des Grégarines. (Bulletins er 
emie Royale de Belgique, xxxi. 1871.) - 
sta. 
*The Gregarinæ and Ameb constitute Hæckels group of Protop: i 
