48 General Morphology o£ the Protozoa 



(Fig. 1, 21, B) and that of Vorticella wind through much of the endoplasm, 

 while that of Conchophthirius caryoclada (117) is irregularly lobate (Fig. 

 1. 21, A). The two slender macronuclei of Spathidiiim spathula (235) ex- 

 tend nearly the length of the ciliate and may sometimes be joined pos- 

 teriorly. In various species of Spirostomiim and Stentor (Fig. 1. 21, F) 



Fig. 1. 21. Macronuclei. A. Conchophthir'nis caryoclada; diagrammatic; 

 x440 (after Kidder). B. Euplotes; diagrammatic; x460 (after Turner). C. 

 Ichthyophthirius multifiliis; x630 (after MacLennan). D, E. Nyctotherus 

 gyoeryanus, longitudinal and transverse sections; karyophore attached to 

 macronucleus; diagrammatic (after Grasse). F. Stentor type; diagrammatic. 

 Key: k, karyophore; m, macronucleus. 



there is a chain of macronuclear nodes joined by filaments. In certain 

 ciliates, the macronucleus is suspended from the cortex by a fibrillar 

 "karyophore" (Fig. 1. 21, D, E). 



The significance of nuclear dimorphism remains uncertain. It is usually 

 assumed that the macronucleus is involved in metabolic activities. In this 

 connection, the extensive resorption of the macronucleus during starva- 

 tion of Stentor coeruleiis (223) is of interest. The micronucleus is sup- 



