HEMOGLOBIN CRYSTALS OF RODENTS' BLOOD 181 



On the Haemoglobin Crystals of Rodents' Blood. 



By 



W. D. Halliburton, *!.!>., B.Sc, 



Assistant Professor of Physiology, University College, London. 



(From the Physiological Laboratory, University College, London.) 



The crystals of haemoglobin since their first discovery have 

 been described by various observers as occurring in no less 

 than five out of the six crystallographic systems. Subsequent 

 investigators have reduced this number to two, namely, the 

 rhombic system, in which the haemoglobin from the blood of 

 most animals crystallises ; and the hexagonal system, in which 

 that from the blood of certain rodents is said to crystallise. 



This research was undertaken at Professor Lankester's sug- 

 gestion, in order, first, to ascertain whether these six-sided 

 crystals really belonged to the hexagonal system ; and, secondly, 

 to find, if possible, an explanation of the difference of crystalline 

 form that haemoglobin presents in different animals, while in 

 its other chief properties haemoglobin is universally the same. 



It will be convenient to take the subject under the following 

 heads : 



1. Historical. 



2. Hexagonal blood-crystals. 



3. Influence of the other constituents of the blood on the 

 crystalline form of haemoglobin crystals. 



4. The crystalline forms of haemoglobin obtained by mixing 

 the blood from different animals. 



5. Can squirrel's haemoglobin be obtained in any form other 

 than hexagonal crystals? 



6. Conclusions and remarks. 



