1890-91.] AMPHIBIA BLOOD STUDIES. 239 



sources analysed by different chemists present so many variations in 

 composition as to lead some observers, Gamgee* amongst them, to deny a 

 chemical individuality to these substances. The nucleins so extracted 

 can hardly be considered as more than derivatives of the chromatin 

 substances, for the latter in the living cell is undoubtedly the seat of the 

 more important vital processes, and the changes resulting in these vital 

 phenomena can hardly occur in a compound so comparatively simple as 

 the nuclein, to which Miescher ascribed the formula C2 9 H^g Ng P3 O22- 



I have succeeded during the last summer in definitely demonstrating 

 that the great part, if not the greater part of the yolk of the ovum of the 

 frog and of Necturus is derived by diffusion from the chromatin of 

 nucleus of the ovumf. Now this chromatin so diffused is the analogue in 

 amphibian &^% of the haematogen of the hen's ^^^. This taken in con- 

 junction with the fact that the iron-holding nuclein of milk can apparently 

 and possibly, only be the chromatins which NissenJ has shown that the 

 degenerating cells of the mammary gland throw out into the lumen of 

 the secreting tubules, distinctly points to the presence of iron firmly com- 

 bined in the chromatin of every cell. 



All these points support and confirm the view that the haemoglobin of 

 the blood is derived from the chromatin § of the haematoblasts. It may 

 be asked, Why if chromatin contains iron, should not all cells contain 

 haemoglobin ? All cells do not contain the excess which haematoblasts 

 have, and therefore have none to spare for transformation into that com- 

 pound. Why the haematoblasts have an excess of chromatin I shall 

 endeavor to show when I come to speak of their origin further on. 

 Enough has been said to show that the compounds which Bunge and 

 Zaleski isolated and called respectively hcematogen and hepattn do not 

 merit these names, the haematogen not going directly, except probably in 

 developing muscle fibre in larval amphibia, to form haemoglobin, while 

 Zaleski has not shown that every cell of the body does not contain a 

 nuclein in which the iron is as firmly combined as in the so called hepattn. 



As an additional proof that haemoglobin is derived from chromatin, the 

 occurrence of phosphorus in the haemoglobin of the blood of the goose 

 may be quoted. It is suspected by many that the phosphorus belongs 



•Physiological Chemistry of the Animal Body, Vol. I., p. 243. 



+The results of the research will be published shortly. 



J\rch. fiir Mikr. Anat., Bd. XXVI., p. 337. 



§1 am inclined to believe, from the results of my own observations, that the haemoglobin of 

 muscle fibre in Amphibia is derived directly from the yolk chromatin or, as Bunge calls it, 

 haematogen. 

 16 



