On the development of the blood and blood-vessels, being the prize essay for 1854 of the Edinburgh Harveian Society / by James Drummond, M.D.

Drummond, James

Date:: [1854]

Credit: On the development of the blood and blood-vessels, being the prize essay for 1854 of the Edinburgh Harveian Society / by James Drummond, M.D. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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$THE •jPLOob jAiib^)Eg,oaii>rf J§;.ss the white.or ^-coburless cells of the ,bJpod (fig. .6, d). A few of them p-esent .vn^ore ■ or less, oval form, and ciontaiu fewer, grajiulcs. thap tiie P.thers. 4th, Oval blood corpuscles,, presenting a distinct yeliQ-\v cpl;ouiV flattened, and'containing small oval ny;9lei' (fig. 6, c). The latter appear when seen whhin the corpuscles, as aj. dar.k shadow. When the blood corpuscles are seen upon their edge, the'nucleus is o})§ierved: as.^ismgll projection; o?i either ;.$3de of,;the.,corpuscle. Addition of acetic acid dissolves the cell \vall, setting free the nuclei, when these appear as small oval finely grauu^ar. bodies. The greater portion of the blood corpuscles just described agree in their general chai-acters with those in the, perfect animal,; In a.few^ of them w'e find two or three bright refracting particles, of spherical form, sipiifar to those contained in the cells, No. 3, ; Lastly, There, are • almost •'Mways present in the blood of the chick more or fewer free, granules of various sizes from a mere point up to, about the if.y'o^tli of an inch in diameter. Some of these are slightly coloured,..and present a small dark point in their interior (fig. '6,.e). : Between the colouring matter contained in the. blood corpuscles and that of the yolk there is a very great i'eseHvJ)ianee. , ; Occasionally in soijie .of the corpuscles we find, after addition of dilute acetic acid, two nuclei'similar to whatFahrner and Kollike iiave described as occurring in the blood c^puscles, o^.the fpjt^il . mam.mal. . ' ••;-' -'r d i;i From this period onwards the only changes which take place are the gradual disappearance of the laa'ge cells above ,desqribed, and the increase in the number of the oval coloured cell^. ..,Almo,st, all the changes which, taliie place ,in jthe ;deveiopjiient of,the..'blood in tlje chick are so rapid that it is difficult to trace them. In general, most of the changes , which take ;place before the appearance of the oval blood corpuscles sesem to: befcpmpjeted before the 36th lipur of in- cubation. . . : . . In blood from' the chipk on the ISth' day of ©^■!^ii^'- ' incubation, there, are very few,. sp,np,etimes ,none, ■ .;^4''a;^\ of-^he, large cells describe^l l aiid.^jQjresent. It consists almost OHtireiy of the cprpii^scles 3 and i^iMf!^^'' 4, with a number of free granules simiiai^to .those already described. There ai'e,,liowever, inpt; in- frequently present bodies which have the same oval shape as the blood corpusples, but are either ' j'^]'® eolourlessL: pr verY..sliij;htly coloured. They do fifteen days after mcu- . ' J \- ^- ^ n i tation; a, Blood cor- not,, moreover, prcscut the (listnict, flattened ap- ;pusck' of second set; b; pearaiicc of the blood corpuscles. They also con- Colourless corpusclo: c, 1 • i ■< ^ , ' i ' Oval, (jrannlar colour- i-^' ''■^^ o^'^i granular nucicus, and sometimes a less corpuscle, a transi- few granules (fiff. 7). tioii stuKc between the c .i' ii i i i i i i 1 two former bodies; cl, oome ot tile oval coloured blood corpuscles ;.Granule ivitii' ceiitral contain a fti'anule or two of a brisiht rcfi-acting spot. 250 diam. ^ t , j appearance. During the development of the blood in the chick, it seems pr,o)>$