72 THE STRUCTURE OF THE RED BLOOD CORPUSCLES. [BOOK I. 



The views The structure of the red blood cell has been a matter of 



of observers the greatest interest to histologists and physiologists, chiefly, 

 espectingtne it must be confe^a, O n account of the important part the 

 cotoured 6 red blood cor P uscle has played in the Theory of Cells. A 

 blood corpus- brief re view of the opinions which have been held will 

 des. here be attempted. 



One view of the structure of the red disk in man is to 

 be mentioned rather because it is curious than because it is important. 

 Delia Torre 1 sought to explain the well-known optical characters of the 

 centre of the disk by supposing that the red corpuscles were in reality little 

 rings. Excluding this view, the remaining discussions of the structure of 

 red blood corpuscles may be grouped under two main questions and a sub- 

 sidiary one. Has the red corpuscle of man a mwleus ? Has the red cor- 

 puscle generally a cell-membrane ? And the corollary question to the 

 latter, Does the red colouring matter reside in the contents of the vesicle or 

 in the membrane ? 



A nucleus was early detected by Hewson in the red blood corpuscles 

 of the frog, and for some time it was tacitly assumed that a similar struc- 

 ture was to be found in the corresponding corpuscles of mammalia. But 

 it should be clearly kept in mind that, from the first, it was analogy rather 

 than direct observation which supported this view. Accordingly we find 

 the red corpuscles of man playing the part of a non-nucleated cell in the 

 reform of the old Cell Theory which was consummated in 1861. In more 

 recent days the only supporter which the original doctrine has found has 

 been Bottcher 2 . For the present, therefore, we may regard the red cor- 

 puscles of mammals as non-nucleated. 



The question of the membrane was longer and more hotly debated 

 than that of the nucleus. As early as 1685 the red corpuscles were spoken 

 of as vesicles 3 ; and by many subsequent writers, among whom we may 

 mention Hewson and Wells 4 , the same doctrine is openly held. Wells 

 is said to have been the first to discuss the question systematically, bringing 

 in support of his view the facts of the action of water and saline solutions 

 upon the red cell. To the names of Hewson and of Wells we must add 

 that of C. H. Schultz, who was believed by Schwann 5 to have been the 

 first to demonstrate the vesicular nature of the blood cells. Schwann 

 himself (fee. cit.), as is well known, maintained the same view; and for 

 many years afterwards it was the prevailing doctrine. Excluding the 

 botanical prejudices of Schwaim's Cell Theory, the only definite grounds 

 for the belief in the vesicular nature of the red cell were the appearance 

 of the cells when irrigated with water and solutions of salts. In the 

 case of the former, the cells swell up and become globular, with a diameter 

 less than the long, and greater than the short, diameter of the original 

 flattened disk. In the case of saline solutions of greater density than 

 the normal blood plasma the outer surface of the corpuscles assumes a 



1 Delia Torre, Nuove osservazioni microscopiche. Naples, 1776. Milne-Edwards, 

 Le$ons, Vol. i. p. 63. 



2 Bottcher, Virchow's Archiv, Bd. xxxvi. and xxxix. (See Article "Blood Corpuscles" 

 in Strieker's Handbook.) Quarterly Journal of Hicroscop. Science. N. S., Vol. xvn. 

 1877, p. 377. 



3 Bidloo, Anatomia humani corporis, 1685. Milne-Edwards, Legons, Vol. i. p. 66. 



4 Wells, " On the colour of the blood." Phil. Trans. 1797, p. 429. Milne- 

 Edwards, Lemons, Vol. i. p. 66. 



5 Schwann, "Microscop. Researches." Syd. Soc. 1847, p. 67. 



