18 On the Cellular Structure 



a cell wall with semi-fluid contents ; especially as the existence of a 

 membrane has been inferred rather than demonstrated." 



Professor Lionel Beale observes, on p. 169 of his work entitled 

 ' The Microscope in Practical Medicine :' — " The red blood corpuscle 

 of man, and mammalia generally, consists of a mass of soft viscid 

 matter, perhaps of the consistence of treacle, composed of hsemato- 

 crystalline. It is, at least in certain states, soluble in water, but is 

 only dissolved by serum and the fluid part of the blood very slowly. 

 The outer part of this matter is of firmer consistence than the 

 interior, especially in the older corpuscles. When the latter are 

 placed in water the more soluble matter is dissolved, leaving the 

 harder external portion." Dr. Beale further recounts sundry con- 

 siderations which, he says, prove conclusively " that the red blood 

 corpuscle is not a cell." 



The distinguished French physiologist, Professor Ch. Piobin, 

 supports similar views, asserting, on p. 697 of ' Dictionnaire de 

 Medeciue, de Chirurgie, &c.,' * — " The red blood corpuscles are con- 

 stituted of a homogeneous mass of globulin which is imbibed by or 

 united molecule by molecule to the colouring matter, or heematosine, 

 and a certain quantity of fat and sahne materials. In mammals, 

 the whole mass is homogeneous, and without any nucleus after the 

 period when the human embryo, for example, attains a length of 

 about an inch ; but previous to that the globules, having a magni- 

 tude of from "010 to "Oil of a millimetre, possess a little round 

 granular nucleus. In all the oviparous vertebrates the globule, 

 whatever its form, encloses a colourless 'spherical or oval nucleus, 

 insoluble in water and acetic acid, while the red mass is soluble in 

 these menstrua." 



In the course of some researches of my own, however, " On the 

 Detection of Eed and White Corpuscles in Blood Stains," t I have 

 shown, first, that if a few drops of fi'esh blood be stu-red up in 

 many times its bulk of pure water, the coloured haemato-crystallin 

 will be dissolved, while a whitish insoluble residue, found under the 

 microscope to be composed of transparent hyaline spheres about 

 :r^^oo th of an inch in diameter, subsides to the bottom of the vessel ; 

 secondly, that if a fragment of dried blood-clot is exposed to the 

 action of a cm'rent of fresh water, the haemato-crystallin will, after 

 a few minutes, be washed away, leaving an aggregation of what 

 appear to be similar delicate cells, altered in shape by mutual pres- 

 sure, but stdl preserving much of their rounded contour; and 

 thirdly, by a calculation of the superficial area of the human red 

 blood disk, based upon accurate measurements of its dimensions 

 when magnified nearly 1800 times, that supposing a cell wall to 

 exist, there would be almost precisely enough membrane contained 



* E. Littre et Ch. Eobin, Paris, 18G5. 



t ' Am. Jour, of Med. Sciences,' July, 1869. 



