The Structure of Colored Blood- Corpuscles. 293 



— the effect of dilute alcohol — " proves the existence if not 

 of a membrane, at' least of a differentiated cortical layer." 1 

 Schmidt s calls attention to the double contour as being 

 " the only proof of the presence of a membrane, whether pre- 

 existent or artificially produced." In fresh blood of Amphi- 

 uma he has observed colored blood-corpuscles with a greenish 

 border, indicating " the existence of a thin layer at the sur- 

 face, differing if not in chemical composition at least in den- 

 sity from the substance of the disks." He has frequently 

 met with " specimens of blood-corpuscles, on which, by a 

 contraction of the protoplasm representing the greater portion 

 of the whole body, the pellicle in question appears separated 

 from the latter." Once he saw a fragment of a corpuscle on 

 which " the membranous layer was seen projecting on the 

 torn surface ; " and at another time he found " a fresh blood- 

 corpuscle of the Amphiuma on which the membranous 

 layer had apparently burst and retracted, leaving a portion 

 of the underlying material, the protoplasm, exposed." He 

 says : " The changes taking place in these blood-corpuscles, 

 when treated with the solution of the hydrate of chloral, are 

 very interesting and important; as they manifestly show the 

 existence of the membranous layer of these bodies, such as 

 I have described it. Thus, after the solution has been ap- 

 plied, the protoplasm of the blood-corpuscle, without much 

 or any alteration of form, gradually contracts upon the nu- 

 cleus. As the result of this contraction, it becomes entirely 

 separated from the membranous layer, which manifests itself 

 in the form of a delicate double contour. The interspace 

 left between the contracted protoplasm and the double con- 

 tour, representing the membranous layer, is very considera- 

 ble, as will be seen from the drawings; and it seems to me 



(1) "De l'emploi de l'alcool dilue en histologic." Archiv de physique. 1874, pp. 790-793. 

 And again, ■■ Kecherches sur les elements du sang." Id . 2. Serie. vol. II, :875, pp. i-15. 



(2) " The structure of the Colored Blood-corpuscles of Amphiuma tridactylum, the Frog, 

 and Man." Journal of the Royal Microscopical Society ; containing its Transactions and 

 Proseeiia^s, with other Microscopical Intelligence, London, Vol. I, No. 2 (May, 1878), pp. 

 67-74 ; No, 3 (July, 1878), pp. 67-120. 



