SO W. H. GILBURT ON THE STRUCTURE AND 



to in the protoplasm I have also seen. As to the chlorophyll 

 bodies, he has in all probability noticed the appearance described 

 by Pringsheim which they present after the removal of the hypo- 

 chlorin, and which resembles in a striking degree that of one of 

 the simpler and coarser spherical Polycistins. 



In 1880 Herr Schleischer published an account of investigations 

 he had made on living cartilage cells. He found that the proto- 

 plasm was formed of two elements, one almost homogeneous and 

 liquid, the other solid and contractile. He also describes certain 

 bodily movements of the nucleus, and says that they are due to 

 the solid elements of the protoplasm, and to those alone.* 



In the same year we have Professor Schmitz bringing forward 

 corroborative evidence concerning the observations of Fromrnan's 

 already referred to. According to him, " the protoplasmic body 

 consists of a reticulated framework of extremely fine fibrillar, vary- 

 ing much in their development ;" u the intermediate substance be- 

 tween the meshes of the fibrillar framework is a homogeneous fluid ;" 

 and i: the framework of fine fibrillar does not consist of rigid im- 

 motile fibres, but of a living motile protoplasm, which is continu- 

 ally undergoing change of form." f 



MM. Treub and Mellink also, in treating of the embryo-sac of 

 Lilium bulbiferum, describe a " ray-like disposition " of the proto- 

 plasm " around the nuclei, it being specially marked when the 

 latter were in process of division." £ This also I am pleased to 

 have seen, though not in the same species, and I strongly suspect 

 that it has direct connection with the structure of the protoplasm. 



Such is the evidence for the presence of structure in this living, 

 growing substance, and taken together as referring both to 

 animal and vegetable cells, I cannot help thinking that, while it 

 does not prove its general existence, it is more than sufficient to 

 cause us to suspend our judgment in the matter. 



We pass on now to a consideration of the Nucleus, which 

 hitherto we have only incidentally referred to. That this body is 

 of great importance was, as we have seen, very early recognised, 

 and the value of the cell was made to depend upon its presence or 

 otherwise. As to the origin of the nuclei, and the formation of 

 cells around them, various theories have been held, one of 



*"J. R. M. S.," vol. iii., p. 408. 



t " J. R. M. S.," series 2, vol. i., p. 475. 



\ " J. R. M. S.," series 2, vol. i., p. 621, 



