230 TRANSACTIONS OF THK CANADIAN INSTITUTE. [VoL. II. 



corpuscles of the Amhlystonia larvae illustrates this variation also (Figs. 

 5, and 7), the corpuscles treated with Flemming's fluid frequently 

 presenting a coarse network ; those made with acetic methyl-green 

 showing a fine one, while those. fixed with osmic acid showed none at all. 



If there is a stroma or any network, it does not separate itself from the 

 haemoglobin, when the latter crystallizes, even in the corpuscle. I have 

 often watched in the moist-stage chamber the cr3'stallization of the haemo- 

 globin, especially when the instrument permits a slow evaporation of the 

 water of the blood, and found on the border or edge of the drop that the 

 haemoglobin contents of a single blood corpuscle crystallized without 

 exuding from or passing out of the cell membrane. In some cases the 

 latter was seen to be more and more pushed out at certain points until 

 it possessed a rhomboid form like that of the contained crystal. The 

 membrane became invisible when evaporation passed a certain limit owing 

 no doubt to the greater density of the medium (serum). These crystals 

 are usually of the same length and breadth as the original corpuscle and 

 they contain, moreover, a large central oval space, the cavity of the 

 nucleus. Now these crystals differ in size, but not in form, from those 

 obtained by rupturing the corpuscles and slow drying of the blood. In 

 the latter the crystals are very long and narrow. If there is a stroma 

 wh\- does it not interfere, not only with the crystalline form, but with 

 the power of crystallization in the haemoglobin? 



The nuclei measure 20 — 2i,« by i2/>i. With ordinary powers (Zeiss Z>), 

 they appear homogeneous, less deeply shaded than the disc, the haemoglo- 

 bin tint which they may appear to have being merely due to that of the 

 superposed portion of the disc, and they often are uncolored or whitish 

 in contrast with the latter. With high powers, such as oil-immersion 

 objectives, one can, in a perfectly normal and fresh corpuscle, determine 

 the existence of a wide-meshed network. This is formed sometimes of 

 thick, sometimes of thin trabeculae, and it is often straw-yellow in color, 

 in other words, it apparently contains hemoglobin. 



I now leave the description of the red corpuscles to take up the 

 question of the origin of haemoglobin in them. 



C. THE ORIGIN OF THE H.^^IMOGLOBIN IN THE RED DISCS. 



If cover-glass preparations of the blood o{ Necturus or portions of the 

 spleen of the same animal be fixed in various ways it will be found that 

 the haemoglobin of the red cells in the different preparations is obtained 

 in various degrees of preservation. 



One of the most convenient fixative reagents for haemoglobin in the 



