354 ELEMENTARY BIOLOGY. [CHAP. 



Kleinenberg's fibres (Sect. 5. d. /?) ; one or more of 

 these may be connected with an individual- cell. 

 They arise as outgrowths of the constricted cell-base, 

 the whole frequently having the appearance of an 

 inverted T with a thick stem (cell-body) and greatly 

 elongated arms (the fibres). 



b. The cells of the interstitial tissue (cf. Sect. 5. e. /?) much 

 smaller than a, and often separable from one another 

 only with difficulty. Numbers of them will be found 

 to contain two nuclei (evidence of active division). 



c. The nematocysts ; highly refractive bodies to be found 

 in both a and b — in the latter in abundance and in 

 all stages of development. Look for the under- 

 mentioned (cf. Sect. 3). 



a. The larger nematocysts; each consists of a body, 

 ovoidal and truncated, with a strongly-marked 

 double contour due to the thickness of its wall; a 

 neck, inverted and beset by three or four powerful 

 spines; a fila?nent, lying within the base of the 

 body, coiled into a spiral the edges of which may 

 occasionally be seen (cf. Sect. 3). 



• Compare a large nematocyst in the everted state ; 

 the summit of the neck is beset by a series of ex- 

 cessively delicate spines. 



/2. The smaller nematocysts ; rarely present in the larger 

 cells. Each is ovoidal and much smaller than a, 

 having a similar double contour. The filament ; 

 but \ to T 5- the length of, and very much stouter 

 than, that of a ; at rest looped, in eversion fre- 

 quently spiral (cf. Sect. 3). 



