STRUCTURAL RELATIONS OF RED BLOOU-CORPUSCLES. 391 



blished for the first time, as far as it can be established anatomi- 

 cally, by the observations communicated above. 



AH methods which have been employed by others in the 

 examination of the red blood-corpuscles, however interesting 

 may be the facts that have been made known by them, have 

 proved insufficient to ascertain the minute structure of the red 

 blood-corpuscles, because they all of them considerably alter and 

 destroy their structure. To these belong the mechanical crush- 

 ing of the blood-corpuscles, the treatment with electric currents, 

 the application of heat and cold, and the employment of the 

 chemical reagents hitherto in use. 



In my first investigations ('Virchow's Archiv,' vols, xxxvi 

 and xxxix) I endeavoured to employ methods which alter the 

 red blood-corpuscles as little and as slowly as possible (blood 

 serum and aqueous humour). Now, I have chosen an entirely 

 diff"erent course, since I have aimed at hardening the blood- 

 corpuscles and then extracting the hsematin from them. I 

 achieved this partly by means of the alcohol-acetic-acid treat- 

 ment, but still better by means of a concentrated alcoholic solu- 

 tion of corrosive sublimate. Both means employed by me — the 

 decoloration by aqueous humour, and the decoloration by corrosive 

 sublimate — although so diff'erent, have led to the same results in 

 regard to the structure of the red blood-corpuscles. If it be, 

 therefore, a question of establishing the advantages these methods 

 possess over those of others, this fact must procure them recog- 

 nition. 



In conclusion I cannot refrain from alluding to the question 

 of the contractility of the red blood-corpuscles. As is well 

 known, it was brought forward by Klebs, but was then pretty 

 generally denied ; and no doubt correctly in regard to the 

 phenomena of motion, which are exhibited by other cells, e.g. 

 the colourless blood-corpuscles. 



There can be no question of a spontaneous locomotion in the 

 case of the red blood-corpuscles. Motion of this sort has never 

 been observed by any one, for the movements of the mulberry 

 and horse-chestnut (thorn-apple) forms, which rock on indivi- 

 dual points, may at once be classed as molecular movements, 

 and left out of consideration. 



Neither can the alterations mform occurring in the red blood- 

 corpuscles be compared to those of the colourless blood-cor- 

 puscles. A constant change in the contour of the corpuscle, 

 and in the arrangement of the individual particles, is entirely 

 absent in the former. When the red blood-corpuscles have 

 assumed a certain form, it appears to remain permanent for a 

 considerable time, even under circumstances in which the colour- 

 less blood-corpuscles always change their shape. Changes in 



