STEUCTUEE OF COLORED BLOOD-COEPUSCLES. 83 



early observation of the rolling nucleus (erroneously ascribed by him, after 

 Schwann, to Schultz instead of to Hewson) agreed with what he himself had 

 seen, and, at least so far as red corpuscles of the blood of salamanders are 

 concerned, positively declared a membrane normally to exist.* As proof of 

 the existence of a membrane, and of its taking no part in the formation of 

 blood-crystals, Bryanowski refers to his success in demonstrating it by means 

 of distilled water, t Owsjannikow says : "To prove with certainty the exist- 

 ence of the membrane is no easy task. Preparations occur which seem to be 

 convincing that there is no membrane ; but other preparations show it with- 

 out the addition of any re-agent. The interior contents retract away from it, 

 so that between it and the yellowish colored contents an empty space remains. 

 Still more distinctly than in pure blood is the membrane seen on the addition 

 of a weak solution of sugar, either without or with admixture of a little 

 alcohol. Then it appears in many, or perhaps in most, of the blood-corpuscles." 

 Furthermore, he describes interior crystallization in which he has seen the 

 membrane pushed out lengthwise by a crystal, and other cases in which 

 " the membrane becomes very distinctly visible as it passes from nucleus to 

 crystal." With high magnifying power, he says, human red blood-corpuscles 

 not seldom show a very delicate membrane ; and one of his conclusions is : 

 u In the blood-corpuscles of most animals an independent membrane can be 

 proved to exist, which behaves toward serum, water, etc., differently from the 

 cell-contents, and which occasionally possesses considerable firmness. " J 

 Richardson argued in favor of the same view, mainly on account of experi- 

 ments upon the gigantic blood-disks of the menobranchus, in which " crystals 

 of haamato-crystallin were seen to prop out a visible membraneous capsule." 

 More recently, Richardson exhibited before the members of the Section on 

 Biology of the International Medical Congress of Philadelphia, a slide with a 

 colored blood-corpuscle of the amphiuma tridactylum, of which it is reported 

 that "the imperfectly crystallized cell-contents occupy the upper end, while 

 the oval granular nucleus fills the inferior extremity, leaving the membraneous 

 capsule relaxed and wrinkled longitudinally, hanging like part of a half-flaccid 

 balloon between them." || Arloing, as the result of his observations, H ascribed 

 a membrane to red blood-corpuscles. Kollmann, after expressly declaring 

 that when he uses the word membrane in relation to red blood-corpuscles, he 

 means to speak of what maybe called an "artefact," *. e., "that apparent 

 membrane which is made visible by the action of reagents,"** discusses the 

 arguments pro and con, and concludes that "the adherents of a membrane 

 have for their opinions at least as many reasons as the opponents." tt He 

 himself believes in " the existence of a membrane in the fresh condition, 



* " Ueber amceboide Blutkorperchen." Virchow's Archiv, vol. xxx. (1864), p. 437. 



t " Beobachtungeu iiber die Blutkrystalle." Zeitschrift fur wissenschaftliche Zoologle, 

 vol. xii., Heft 3 (November 17, 1862), p. 317. 



t"Zur Histologie der Blutkorperchen." Bulletin de 1'Academie des Sciences de St. 

 Petersbourg, t. viii. (1865), pp. 564, 568-570. 



\ " On the Cellular Structure of the Red Blood-corpuscle." Transactions of the American 

 Medical Association for 1870, pp. 259-271. 



|| Transactions of the International Medical Congress of Philadelphia, held in 1876. 

 Philadelphia, 1877, p. 488. 



IT " Recherches sur la nature du Globule Sanguin." Compt. Rendus, t. Ixxiv. (1872), 

 No. 19, pp. 1256-1259. 



**"Bau der rotheu Blutkorperchen." Zeitschrift fiir wissenschaftliche Zoologie, vol. xxiii., 

 Heft 8 (November 18, 1873), p. 467. 



\M\)iil., p. 482. 



