The crescent forms of the erythrocyte in normal and pathologic blood expressions : origin of red blood corpuscle and blood plasm / by Frank A. Stahl.

  • Stahl, Frank August, 1862-
Date:
[1887?]
Catalogue details

Licence: Public Domain Mark

Credit: The crescent forms of the erythrocyte in normal and pathologic blood expressions : origin of red blood corpuscle and blood plasm / by Frank A. Stahl. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    CONCERNING ORIGIN OP THE BLOOD CORPUSCLE IN THE CHORION IN THE HUAIAN. Tt is a Avell known admission that blood corpuscle and blood circulation are extra-embi'vo in origin. But from where primal blood cor])uscle, plasm, and circula- tion; how developed and in and from what ti.ssues have ever been open (questions for difficult and original solutions; but not till today have they met with any happy results. For origin of blood corpii.scle, until today, especially, are mentioned Blood Islands and Yolk-Sac (potential yolk-sac) ; both, not primary bnt secondary auxiliary developments, depend- ing upon the chorion for growth and development. But how does such growth and development occur, except through some afferent pabulum bringing circulation ; surely not an autogenous growth! proving such (their) growth secondary to an anterior circulation. Also among such sources of origin may be mentioned the well known theoiy of the uu'dulla. The medulla of the bone in this connection s])ells continuation, not origin of blood corpuscle. Blood cor])uscle, i)la.sm, and circulation in origin, is in the chorion and is easy of histologic proof. In a series of -slides from a 2-.‘lrd week ovum, the primary EXPLAXATrON.S OF FlGUKES 3 AND 1. Fig. 3.—The normal non-nucleated cre.scent, found in another blood ve.ssel of the chorion of 7-8th week human ovum. Another example of intra-blood vessel differentiation. Note the delicate nucleus, apparently just extruded into the hollow of the crescent. 1. Non-nucleated cre.scent ty])ed erythrocyte with extruded nuclevis in hol- low of crescent. 2. Inwandering elongated or spindle-shaped nuclei undergoing: division and multiplication differentiation from the large round n\icleus of the second row ; they enter blood stream and metamorphose into erythroblasts. Margin of blood space vessel seems endothelial, hut not so, they are concentrically ar- ranged spindle-.shaped nuclei only, ready to enter blood stream. This picture lends explanation to the theory formerly held, that endothelial proliferation affords origin to red blood corpuscle, the erythroblast. Refer to Fig. 10 below, where vessel wall lumen again is seen without endothelium. This, no endothe- lium, feature is also seen in -so important vessels as the umbilical arteries and vein of the umbilical cord at the ,')-6th week ; human ovum. 3. Erythroblasts in villus stroma blood space. 4. Elongated blood space vessel with erythroblasts within ; no endothelium. 5. Spindle nuclei ready to subdivide into several offspring and enter blood stream. Fig. 4..—The normal cup-shaped erythrocyte, found in the Area Vasculo.sa of a 7-8th week human ovum. An example of blood corpuscle division and multiplication differentiation in the delicate arachnoidal connective ti.ssue from the area vasculosa. Cup-shaped crescent. In surrounding me.shes of area vasculosa. many j'oung mature non-nucleated erythrocytes. To the left large erythroblasts with several nuclei; pre-multiple division by amltosis, into several offspring; one offspring for every nucleolus.