142 



HISTOLOGY. 



With the loss of the nuclei the red corpuscles become smaller and cup 

 shaped; they are convex on one side and concave on the other. ('Bell 

 shaped,' implying a flaring rim, is a less descriptive term; 'saucer shaped,' 

 signifying that they are often shallow cups, has lately been employed.) 

 The protoplasmic reticulum has disappeared and the mature corpuscle 

 has been said to be a drop of dissolved haemoglobin enclosed in a mem- 

 brane. With special methods a granular network has been demonstrated 



in some apparently homogeneous corpus- 

 cles. Others in the same preparation 

 may contain no reticulum. The network 

 has been interpreted as the remains of the 

 original protoplasmic net, and also as an 

 artificial decomposition of haemoglobin. 

 It occurs especially in the newly formed 

 corpuscles (seen in cases of anaemia). 

 Instead of a net there may be rings or 

 round bodies the nature of which is not 

 clear. The existence of a membrane 



around the corpuscles is still debated. It does not stain distinctly, 

 and seems to blend with its contents. Sometimes it is described as an 

 exoplasmic, fatty layer. The osmotic changes in the corpuscles show 

 that they are surrounded by structures which are not composed of haemo- 

 globin, and which act as membranes. 



Cup shaped corpuscles may be observed circulating in the omentum 

 of a guinea pig. The etherized animal should be placed beside the stage 



FIG. 166. RED CORPUSCLES, SKETCHED 

 WHILE CIRCULATING IN THE VES- 

 SELS OP THE OMENTUM OP A 

 GUINEA PIG. 



FIG. 167. RED CORPUSCLES IN VARIOUS CONDITIONS. 



of the microscope and the omentum spread over the condenser. A cover 

 glass is put directly upon it, and the corpuscles are examined with an oil 

 immersion lens. Some of them drawn free hand while they were under 

 observation are shown in Fig. 166. If a drop of blood from the finger is 

 spread upon a slide in a thin layer and examined at once some cup shaped 

 forms are seen. They soon flatten into biconcave discs, appearing as in 

 Fig. 167, A. Their thin centers appear light in ordinary focus, but become 



