THE EYE OE PECTEN. 73 



cate celi-outliues enclosing them (PI. 1 , figs. 7 and 9). These 

 cells have their ends drawn out into the long fibres seen in 

 macerations so easily, and which are many times the length 

 of the cell-body (PI. 7, fig. 2). In some cases, as Hesse 

 pointed out, a number of fine pai-allel fibrils appear to pass 

 out of and through the cells (PL 7, fig. 7). He regards the 

 fibres as muscle-fibres, and the cell-body as containing the 

 remaining myosarc and nucleus. This view is based on the 

 reaction to picric acid — siiurefuchsiu, which stains muscle 

 yellow and connective-tissue red. I was not sure that they 

 were not connective tissue cells, and in fact believed them to 

 be such. For this reason Mallory's connective-tissue stain 

 was used as recorded on p. 53. The fibres and cells were 

 stained by this process an intense red, against the blue sub- 

 corneal tissue above (PI. 7, fig. 7). They stain therefore as 

 muscle-fibres. Hesse says ([34], p. 397) that these fibres 

 extend to the edge of the lens but not further. 



The same fibres, however, are to be found in the connective 

 tissue extending down the sides of the optic vesicle (PI. 6, 

 fig. 1, M.f.) and often quite near or even on the inner surface 

 of the same. I believe they have a far wider distribution 

 than Hesse supposed. This is the apparatus that, aided by 

 the lens-cells, is (according to Hesse) concerned with accom- 

 modation. Through the contraction of these fibres the outer 

 surface of the lens becomes reduced in extent, the lens-cells 

 are compressed together here, and, being plastic, change 

 their shape, the contents swelling towards the inner surface 

 where there is less tension. The result is an alteration in the 

 shape of the lens and hence of the focus. If the muscles are 

 relaxed the elastic cells (aided by the fibrillee) return to 

 their previous shape and the focus is adapted for more distant 

 objects. No physiological proof has yet been brought to 

 support this theory, and, as far as experiments go, I could 

 find no evidence of accommodation (see p. 102). 



Hesse has built up his theory simply to account for the 

 fibres on the lens and the persistent astral rays in the cells. 

 The function of the latter may be simply to give greater 



