76 On the Nervous Stjstem of Actinia. 



Haimean bodies in the tentacles, and, as will be noticed farther on, 

 I have found them of enormous size in the peristome. 



They are surrounded in those places, but not covered, with 

 pigment cells and granules, and are situated just beneath the nema- 

 tocyst layer in the tentacle, and beneath a corresponding layer, or 

 one of bacilh, in the peristome. I have failed to recognize any 

 nervous elements in the tentacles save the fusiform bodies, and there 

 are none in the peristome except these irregular cells. 



Again, the Haimean bodies are found in the chromatophores, in 

 some places, amidst the Eotteken bodies, separating them. 



Nevertheless it is true that light falling on the surface of an 

 Actinia will reach farther into its structures where there are 

 Haimean bodies, and farther still if the Eotteken cells underlie 

 them. Where there is no pigment intervening between the bodies 

 when placed side by side, or between the Eotteken cells, a diffused 

 glare of hght would impinge on the granulo-cellular layer below 

 them, in which the nerves ramify and the nerve cells exist. But 

 when the pigment granules and cells exist, they break up the 

 general illumination and confine it to a series of separate bright 

 rays. Each of them is brighter than the corresponding space of 

 diffused light ; and it would appear that the bacilli, the Haimean 

 bodies, and the Eotteken cells in combination, concentrate light. 



Two or three bacilli are placed side by side and behind each 

 other over a small Haimean refractile spherical cell, and perhaps 

 twenty or more cover a large cell (PI. LXIX., Fig. 15). Usually a 

 Haimean body is placed immediately over a Eotteken body ; but, as 

 Eotteken has pointed out, this is not an invariable arrangement, for 

 some cover the spaces between and over them. The refractibility 

 of the fluid contents of the Haimean bodies and Eotteken cells 

 appears to be the same ; but the elongated form of the last-mentioned 

 structures may act upon hght as if their internal fluid were more 

 viscid. 



In every instance there is a more or less opaque tissue between 

 the proximal end of the Eotteken body and the nerve cells ; and, 

 moreover, the delicate protoplasmic layer, which is slightly impervious 

 to Hght, surrounds the Haimean bodies. 



In my opinion the Haimean bodies, wherever they exist, carry 

 Hght more deeply into the tissues than the ordinary epithelial 

 structures. This is also the case with the bacilli and Eotteken 

 bodies, even when they exist separately and with or without the 

 Haimean bodies. There are three ordinary constituents of the skin, 

 and through their individual gifts and structural peculiarity they 

 place the Actinia in relation with light. When they are brought 

 together in this primitive form of eye, they concentrate and convey 

 light with greater power, so as to enable it to act more generally on 

 the nervous system — probably not to enable the distinction of objects, 



