The Structure of Colored Mood-tforfltlscleSi i489 



time been taught, was owing more to the silence of the op- 

 ponents than to the force of the arguments of the believers."- 1 

 Vintscligau 1 and Rollett 3 also argued against the existence of 

 an investing membrane; and the opinion seemed doomed. 

 But before the end of the year in which Beale and Briicke 

 contested the existence of an investing membrane, Hensen 

 defended it. 4 He reports having observed in the blood of 

 frogs both in fresh preparations, — i.e., in red corpuscles ex- 

 amined without the addition of any reagent, — and in cor- 

 puscles placed in various mixtures, especially a solution ot 

 sugar, that sometimes the membrane, as a distinct outer con- 

 tour, is lifted up from the interior contents at one or more 

 points of the circumference, these interior contents being re- 

 tracted more or less densely upon the nucleus. A few years 

 later 5 Hensen reiterated his conviction as to the presence of a 

 membrane; it is certain, therefore, that Lankester 6 has misap- 

 prehended his meaning. Kollicker, who had previously as- 

 serted that the red blood-corpuscle possesses "a very delicate 

 but nevertheless tolerably firm and at the same time elastic 

 colorless cell-membrane, composed of a protein substance 

 closely allied to fibrin,"? continued to uphold their vesicular 

 constitution. 8 Preyer reported that the early observation of 

 the rolling nucleus (erroneously ascribed by him, after 

 Schwann, to Schultz instead of to Hewson), agreed with what 



(1) " Die ELementarorganismen." Sitzungsberiohte der Wiener Akademie, vol. 44, Div. II, 

 p. 389 (Read Oct. 17th, 1861). 



(2) •' Sopra i corpusculi sanguigni della rana." Atti del Istituto Veneto, vol. VIII, Ser. III. 



(3) " Versuche und Beobachtungen am BLute." Sitzungsberiohte der Wiener Akademie, 

 vol. 46 (1862), p. 65. 



(4) " Untersuchungen zur Physiologie der Blutkorperchen Bowie iiber die Zellennatur 

 derselben." Zeitschrift fiir wissenschaftliche Zoologie, vol. XI, Heft 3 (Ausgegeben Dec. 

 23. 1861) ■, pp. 253-278. 



(5) In a foot note of an article entitled "Deber das Auge einiger Cephalopoden." Ibid., 

 vol. XV, Heft 2 (April 1, 1865), p. 170. 



(6) Lankester, in his article on the red blood-corpuacle in the Quarterly Journal of Micro* 

 scopical 8cience, Oct., 1871, already cited, says, p. 366, that Hensen "distinguishes a layer 

 of fluid protoplasm surrounding the colouring matter, by cadaveric alteration of which he 

 believes the supposed membrane of the corpuscle to be formed." 



(7) Manual of Human Histology. Translated and edited by Oeo. Busk and Thos. Huxley, 

 London, Sydenham Society, 1854. vol. II, p. 326. 



(8) Handbuch dar Gewebelehre, 1863, p. 627. 



