On the Presence of Iron in Chromatin. 277 



Vine (J. G.) An Explanation of the Constitution of Ether, of the 

 Constitution of Matter, and of the Cause of Universal Gravita- 

 tion. 8vo. 1891. The Author. 



Watts (G.) Dictionary of the Economic Products of India. Vol. V. 

 8vo. Calcutta 1891. The Indian Government. 



Photograph of Dr. Benjamin Franklin, F.R.S., from the Painting in 

 the possession of the Royal Society. Mr. Hyatt. 



" On the Demonstration of the Presence of Iron in Chromatin 

 by Micro-Chemical Methods." By A. B. MACALLUM, M.B., 

 Ph.D., Lecturer in Physiology in the University of Toronto. 

 Communicated by Dr. H. NEWELL MARTIN, F.R.S. Re- 

 ceived April 23, Read April 30, 1891. Revised August, 

 1891. 



The investigation, some of the results of which are to be given in 

 the present paper, was stimulated by the conclusions of studies 

 which I carried on during the last five years, and by the observa- 

 tions of Bunge* and Zaleskif on the occurrence of iron-holding 

 proteids in the food and in the liver. The conclusions which I drew 

 from my studies were : 



(1.) That in Amphibia the hsemoglobin is derived from the very 

 abundant chromatin of the hsematoblasts.J 



(2.) That in the maturing ova of Amphibia the abundant chromatin 

 of the nucleus diffuses out from the latter, and, as the diffusion com- 

 mences and progresses, the yolk spherules appear and increase in 

 size. In other words, chromatin constitutes a large part of each yolk 

 spherule. 



(3.) That there is a transference of chromatin from the maternal 

 tissues to the foetal villi in the placenta of the Cat, and that this 

 chromatin is carried from the central portions of the villi by the 

 amoeboid cells of the latter onwards towards the foetus. 



From the first conclusion it follows that the chromatin of hsemato- 

 blasts contains iron. A consideration of the remaining conclusions 

 points, however, to a wider distribution of iron. Bunge found in 

 the yolk of the hen's egg an iron-holding nuclein, which, from its 



* " Ueber die Assimilation des Eisens," ' Zeit. f . Physiol. Chemie,' vol. 9, p. 49. 



f "Studien iiber die Leber. 1. Eisengehalt der Leber," 'Zeit. f. Physiol. 

 Chemie,' vol. 10, p. 453. 



J The observations on this subject are described in a paper which is to appear in 

 the forthcoming number of the ( Transactions of the Canadian Institute.' 



