332 H. M. BERNARD. 



surrounded with cytoplasm. This eye had been bandaged 

 and very little used before excision ; hence, perhaps, an 

 accumulation of this material. These observations point 

 towards experimental confirmation of our inference that the 

 granular cytoplasm is nutritive, and that, in its passage 

 through the retina, it is seen in more or less accidental asso- 

 ciation with the nuclei. We shall see lower down, when 

 describing the "NissFs Schollen," that the evidence for the 

 streaming of the cytoplasm distally is greatly strengthened. 



In the middle layer, granular cytoplasui is only occasion- 

 ally associated with the nuclei. In mammals in which, as is 

 well known, the capillaries penetrate into this layer, it may 

 surround a nucleus here and there, and even render a syncy- 

 tial chamber turgid. It will be an instructive study to see 

 if any close relation can be found between the capillaries and 

 the distribution of this matter. In this middle layer, how- 

 ever, it is most frequently seen as a small tongue streaming 

 inward into the inner reticular layer, the natural inference 

 being that it is not streaming away, but arriving, having come 

 through the inner reticular layer from the ganglionic nuclei 

 from which, as we have seen, it appears to be streaming. The 

 suggestion is that, as it emerges from the inner reticular 

 layer, it attaches itself to the first nuclei of the middle layer 

 which it reaches. 



This mere transitory association between the granular 

 cytoplasm and the nuclei in the retina is in strange contrast 

 with what we see in most other tissues. In the typical cell 

 the nucleus is always enveloped by what is to all appearance 

 a discrete mass of cytoplasm. A nucleus without cytoplasm 

 has hitherto been thought almost an impossibility, and, doubt- 

 less, for many tissues, e.g. in all epithelia, it is an impos- 

 sibility, the reason why being not far to seek. Assuming for 

 the present what can be easily proved, the existence of a 

 special protomitomic system for each tissue, epithelia repre- 

 sent outer fringes of such systems, and it is inconceivable that 

 the delicate protomitomic filaments themselves should project 

 without some covering; even when they run out into the 



