240 TRANSACTIONS OF THE CANADIAN INSTITUTE. [VoL. 11. 



to a compound which, in no way uniting with the haemoglobin, yet in an 

 admixture with it, is so difficult to separate that after many crystallizations 

 of the haemoglobin some will always adhere to the crystals. Recently, 

 however, Jacquet^ has isolated the haemoglobin of hen's blood after 

 recrystalHzation and has found that it contains o'i97% of phosphorus 

 and 0'335% of iron. Hoppe-Seyler had previously found in the haemo- 

 globin of goose's blood 077% of phosphorus and o*437o ^^ iron. The 

 anomaly of the presence of phosphorus in the haemoglobin of Avian 

 blood is readily explained away by the fact that the haemoglobin is 

 derived from a class of proteids which are peculiar in containing phos- 

 phorus. 



It is, indeed, an important question whether the chromatin of all cells 

 does not act as an oxygen-absorber like haemoglobin. I made some 

 experiments on this point. Methylene blue in living tissues in which the 

 metabolic processes are vigorous becomes discolored owing to the 

 abstraction of oxygen. This reagent has been recently much used on 

 this account in the determination of the course of nerve fibres. Into 

 solutions of this dye I put a number of free-swimming larval Amblysto- 

 mata and examined them from time to time to determine the effect on 

 the cells of the gills and in the tail. With weak solutions I found the 

 free portions of the membranes only of the epithelial cells colored, while 

 with gradually increasing strength of solution granules in the cytoplasma 

 of the same cells become stained, especially those between the radicles 

 of the cilia on the gills. Sometimes a red blood corpuscle presents in 

 the disc in this case one or more blue granules. If one increases the 

 strength of the reagent almost up to the limit of endurance on the part 

 of the animal, other cytoplasmic elements are stained, but in no instance 

 have I seen a single nuclear body stained. This was not due to slower 

 penetration and, therefore, readier deoxidation, or reduction of the dye, for, 

 in the few examples of epithelial cells in division which I found in that 

 stage in which the nuclear membrane is absent, the chromatin elements 

 were absolutely colorless. Indeed, it is only when the dividing cell is 

 moribund or dead that the chromatin elements stain at all. The pro- 

 bable explanation of the phenomena described is that the chromatin has 

 a marked capacity for storing up oxygen in itself and that it differs from 

 haemoglobin in that it gives up this element only to the products of its 

 metabolism. 



If chromatins and the iron-holding proteids derived from them, like 

 the yolk nuclein of Bunge, have the capacity of storing up oxygen, then 

 it is possible that part of the oxygen required for respiratory purposes in 



*Zeit. fiir Fhysiol. Cliemie., Ikl. XIV., pp. 289-296. 



