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the inside of the basket, as mav be seen in the figures. There where 

 no hairs are developed, the glious fibres lie close against the surface 

 of the cell-protoplasm (fig. 8, 10, 11). 



Where Joseph considers the hair-like processes to be only present 

 at that side of the cell which is turned towards the surface of the 

 animal, I cannot agree with him. When we compare horizontal and 

 transverse sections carefully with each other, we must draw the 

 conclusion, that the hairs may be developed on all sides of the cell, 

 except there where the cell-body sends a dendritical process through 

 the glious basket. Even there where the cell is shaped like a cup 

 or calix, at both sides of the cup the cilia may be present (figg. 10, 11). 

 The cilia at the inside of the cup are separated from each other by 

 an ingrowth of the fibres of the glious basket (fig. 10). When the 

 cell is cut at right angles to the axis of the calix, this may lead to 

 the appearance of a ring of protoplasm, at both sides covered with 

 the hairs, and surrounding a mass of coiled-up fibres, the ingrowing 

 fibres of the glious basket (fig. 11). 



The protoplasm of these cells shows a regular network of neuro- 

 tibrillae, which differs from the network of the other cells of the 

 spinal cord by its much larger meshes (compare figg. 8 — 10 with 

 figg. 1 — 6); only at the periphery of the cell, under the hair-like 

 processes, a finer network of neurofibrillae is to lie seen (fig. 8). 

 The hairs themselves seem to be implanted on a layer of small darkly 

 staining granules or small rods, of which the definite structure is 

 difficult to be seen. In many cases it is only represented by a some- 

 what more coarsely granular layer of protoplasm there where the 

 cell-body is covered with the hairs. 



All these things seem to point to the conclusion that these cells 

 do not possess a light-percepting function, as suggested by Joseph. 

 The shape of the cells and the peculiar structure at least are not 

 favourable to the hypothesis. But it is sure, that this group of cells, 

 all presenting the same peculiar structure, has a distinct and peculiar 

 function. The structure of the cells reminds us in the first place of 

 a static organ, and especially cells as- drawn in fig. 9 and fig. 11, 

 seem to suggest such a function. The peculiar baskets of fibres sur- 

 rounding the cells remind us of the cells of Purkin.tk of the brain 

 of the craniotes, but bearing in mind the very little we know about 

 these cells and about the cells just described, it is more advisable to 

 stop at these general suggestions and not to try to go more into details. 

 The suggestion of Joseph at all events seems to me to be untenable. 



A third type of cells differing from those which I described here, 

 is that of the cells of the so-called infundibular organ in the ventral 



