406 RECORD OF CURRENT RESEARCHES RELATING TO 



Origin of the Red Corpuscles of Mammalian Blood.*— Professor 

 Rindflciscli's special contribution to this subject consists in, 1st, a 

 description of the vascular plexus of the marrow of mammalian bones 

 which he has succeeded in injecting (using the rib of a young guinea- 

 pig), and of the wall-less character of its smaller vessels ; 2nd, and of 

 greatest importance, an answer to the question, " How do the nucle- 

 ated red corpuscles of the red bone-marrow give rise to the non- 

 nucleated corpuscles of the blood?" It is well known that this 

 question has always been answered by hypotheses based on very 

 slender foundation. 



The old view as to the origin of the red blood-corpuscles was that 

 the nucleus of certain colourless corpuscles became red and escaped 

 as a free nucleus — the homogeneous red blood-corpuscle. Later 

 knowledge as to the red coloration of the whole of the mother-cell 

 . of the red corpuscle led to the assumption that the nucleus became 

 atrophied and the whole cell converted into the non-nucleated red 

 corj)uscle. The attempts which have been made from time to time 

 during the past few years to detect a nucleus in some form or other in 

 the red mammalian corpuscles, point to a foregone conclusion in favour 

 of this total conversion. 



Professor Eindfleisch has, however, seen, both in embryos and 

 more advanced individuals, the steps in the transformation of the red- 

 coloured cell of the marrow into the non-nucleated red corpuscle, which 

 demonstrate that the nucleus of the red-coloured cett escapes and 

 atrophies, ichilst the body of the cell contracts and becomes the red corpuscle. 

 He gives figures of the red cells with their nuclei in the act of 

 escajnng, lying just on the limit of the cell-body, or protruding from, 

 or even hanging by a mere thread to the latter. Then, beside these, 

 he has seen and figures the freed nucleus and the irregular, collapsed, 

 coloured body of the cell, which will soon be shaped by pressure and 

 rolling into the disk-form of the circulating red corpuscle. He has 

 endeavoured, but unsuccessfully, to witness under his own eyes the 

 actual extrusion of a nucleus from a red cell. At the same time, the 

 intermediate series of forms observed by him are very strong evidence 

 in favour of the view which he takes. 



Professor Lankester thinks that Professor Eindfleisch's view is 

 supported by certain facts of comparative anatomy which he has not 

 himself adduced in its favour. In the Chsetopodous and some other 

 worms, the nuclei of the vascular walls are often loosened and float 

 in the blood as corpuscles. They are not impregnated by haemoglobin, 

 but the plasma, in which they float, is. Whence comes the hajmo- 

 globiu of the plasma ? Clearly, the cells forming the walls of the 

 vascular system in certain regions are in the Chaetopoda, as in Verte- 

 brata, hrematogenous ; in them, as in Vertebrata, the body of the cell 

 forms the hremoglobin, which in this case becomes liquid instead of 

 retaining the form of a corpuscle, and at the same time the nucleus is 

 separated from thehoimoglobin-bearing body just as it is in the Mammalia, 

 but here, as it does not there, enters into the blood stream. 



* ' Arch. Mikr. Anat.,' xvii. (1879) ; see ' Quart. Jouru. Micr. Sci.,' xx. (1880) 

 p. 241. 



