20 ILLINOIS BIOLOGICAL MONOGRAPHS [230 



the outer end only, and that the deep seated nucleus is affected by the 

 very small parasite indicates the untenability of this theory as a cause 

 of cellular reaction to the parasite. 



A theory for the shrivelling of the parasitized cell may be derived 

 from the facts of liquid pressure. The cell wall is normally under 

 some pressure from within, due to turgor. When the cell is punctured 

 by the sporozoite, some of the cell sap might ooze out. Most of the liquid 

 content of the cell is, however, contained in vacuoles and not liable to be 

 affected by the puncture. The viscid cytoplasm of the cell would prob- 

 ably be unable to find exit through the small opening. The puncture is 

 as small as is the penetrating sporozoite and closed by the same. The 

 parasite grows rapidly, enlarging the opening only as fast as the para- 

 site grows. I have in no instance seen a section wherein the cell wall was 

 torn by the growing animal, and in every instance the two fitted together 

 tightly so as to form seemingly one layer at the neck of the epimerite. 

 Thus the theory of loss of cell content by the oozing out through the punc- 

 ture made is untenable. 



MOVEMENT IN GREGARINES 



Movement in Gregarines has probably been observed as long as the 

 animals themselves. Dufour (1837:11) said 



"Leurs movements sont fort obscur et leur locomobilite est d'une lenteur 

 extreme; cependant je les ai constates." 



Siebold (1837:408) doubted that Gregarines were animals for he saw no 

 movements. Kolliker (1848:32-3) described movement of the gliding 

 type as 



"Eine langsam vorwartschreitende Bewegimg ohne sichtbare Contractionen 

 der Leibeshiille." 



He also noted the bending movement and describes it as follows : 



"Bewegung nach dieser oder jener Richtung durch mehr oder minder 

 enefgische, auf verschiedene Weisen sich combinirende Zusammen- 

 schniirungen der Leibeshiille." 



Kolliker did not attempt to explain the cause of these movements but 

 he answered the question raised by Siebold "Are the Gregarines ani- 

 mals?" by describing the violent contractions seen in many of his new 

 species, movements which only animals possess. 



Leidy (1849:232) "detected movements of an animal character," 

 and discovered the longitudinal striations of the epicyte which he 

 thought were muscular in function. 



Van Beneden (1872) discovered the network of transverse fibrillae 

 which Schneider (1875:505) called the myocyte. Contractility of the 



