1890-91.] AMPHtBIA BLOOD STUDIES. 23.3 



do here with achromatic substance is shown in sections of the spleen 

 hardened with Fiemming's fluid and stained with alum-haematoxyUn. 

 In such preparations the nuclei of the red cells take a homogeneous deep 

 stain thus proving that there is no conversion of achromatin into 

 chromatin or into a substance which reacts towards dyes like the latter. 

 Hence we may conclude that the nuclear contents in the red cells are 

 formed of chromatin more or less modified. 



If the nuclei of the fully formed red cells in a larval Anibly stoma 

 hardened in Flemming's Fluid be put under observation, a condition is 

 seen in them similar to that found in the nuclei of the red cells of the 

 spleen hardened in chromic acid, that is, they stain in the majority of 

 cases with alum-hsematox}'lin, alum-cochineal in the same way, taking a 

 uniform homogeneous tint. There can be no doubt that here the nuclei 

 are well preserved. In some larva; again, there are found a few fully 

 formed corpuscles in which the nuclear network alone is stained. There 

 are also other nuclei in such larvae which present different amounts of a 

 stainable mesh substance and the inference gained from the study of 

 such nuclei is that the stainable mesh substance takes its origin in 

 the network and as the latter in the newly formed corpuscles contains 

 the whole of the chromatin, the stainable mesh substance is modified 

 chromatin. That it is modified and no longer fully functional may 

 be seen by glancing at Figs. 13 and 14 which represent fully formed red 

 corpuscles of the larva in division. Examples of the latter are not very 

 rumerous, not more than three or four occurring in a whole series of 

 sections. In these one finds that there is a quantity of chromatin 

 between the loops of the chromatin figure in the daughter nuclei and 

 that this unorganised chromatin has only taken a passive share in the 

 process of division. The latter species of chromatin was in a few cases 

 so abundant as to obscure the regular chromatin loops. 



The substance, then, in the spaces of the nuclear network is a derived 

 chromatin which, fixed with chromic acid or Flemming's Fluid, gives 

 with alum-cochineal or alum-haematoxylin a deep and homogeneous 

 stain and which when fixed with chromic acid has the property of giving, 

 as haemoglobin does, a grass-green stain with the Indigo-carmine Fluid. I 

 believe this modified chromatin is the parent substance of haemoglobin, 

 that is, it is a true haematogen. 



That this modified chromatin is derived from the primitive chromatin 

 of the haematoblast is also shown by a study of sections from the spleen of 

 Necturjis hardened in chromic acid and stained with the Indigo-carmine 

 Fluid. Fig. 8 is an exact representation of a group of cells from one of 

 the blood sinuses in such a section, in which a dividing haematoblast is. 



