STUDIES IN THE EETINA. 333 



finest cilia, they must be thought of as sheathed in cytoplasm.^ 

 No such difficnlty exists in the way of what, for purposes of 

 observation, we may call naked nuclei within the retina, for, 

 as a matter of fact, they are not any more really naked than 

 are the nuclei in many ordinary cells in which there is a 

 perinuclear space. Indeed, as already pointed out, the 

 chambers of the retinal syncytium may be regarded as 

 perinuclear spaces with one or more nuclear nodes of the 

 protomitomic reticulum suspended within them. And round 

 these nuclei, and in close contact with them, an unstable, 

 probably nutritive, granular cytoplasm occasionally accu- 

 mulates. 



One word in passing as to the bearing of this upon what is 

 known as the cell theory. The inadequacy of this theory has 

 long been felt, and has found expression at the hands of 

 eminent biologists,'^ But the attack centres round the fact 

 that the cell doctrine cannot be reconciled with certain 

 phenomena, especially relating to development. The theory 

 does not go deep enough. It has been framed, it is true, 

 with reference to a lai-ge but yet limited number of pheno- 

 mena; further research has been showing it to be super- 

 ficial. The retina has now revealed a continuous fibrillar 

 system (parts of which were already well known) under- 

 lying all protoplasmic structures. This system reduces 

 the " celP' to its true position. It is no longer a mass 

 of cytoplasm containing a nucleus, but a node of a pro- 

 tomitomic system with cytoplasmic matter massed round 

 it. It has long been admitted that the essential of the 

 cell is the nucleus, without which the protoplasm dies, and 

 now we know that the nucleus is, in essence, a specially 

 complicated node of the protomitomic system. This pro- 

 tomitomic system, with its nodes, is the deeper under- 

 lying factor in relation to which these masses of cytoplasm 

 accumulated round the nodes ; that is, the cells are 



' The protomitomic system in general will be described elsewhere. 

 2 See Professor VViiilmaii, ' Wood's Hall Biological Lectures,' 1893; also 

 Professor Sedgwick, 'Quait. Jourii. Microscopical Science,' vol. xxxvii, 1894. 



