Microscopical morphology of the animal body in health and disease / by C. Heitzmann. With 380 original engravings.

Carl Heitzmann

Date:: 1883

Credit: Microscopical morphology of the animal body in health and disease / by C. Heitzmann. With 380 original engravings. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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$<n{i(iis or coLojn-.j) nuxtn-coKruscLES. la) coi-jjiisclos hjive nuclei. Tlie iiuclt'us is evidently not a j-e(|nire- nient of juvenile red l)lo()d-corpuseles. In t'ull-<jfrown bii-ds sueh a new formation of blood-eor- puseles does not occur. In a pigeon nine months (^Id, the layer of globular cartilage-coi-puscles is directly bounded by bone- tissiu'. containing mednlhirv spaces filled with fat. The blood- vessels of these si)aces at their upper ends, looking toward the cartilage, are looped. The intermediate stage of ossification of the basis-sul)stance and new formation of blood-vessels and hajmato- blasts is absent. In still older animals, in whi(;h the layer of hyaline cartilage is much reduced in thickness, the upper ends of the medullar}' spaces toward the cartilage are closed by concentric systems of lamella^ of completely formed bone-tissue. llayem (see ])age 98) in 1877 described small shining lumps in the fluid of l)lood, more numerous in the foetus than in the adult, which he, I think justly, termed haematoblasts. Red blood-corpuscles are very early formations of the middle layer (mesoblast) of the embryo. Probably they originate in every part of the body wherever there is living matter, especially in all varieties of that tissue which is exclusively supplied with ))lood-vessels, viz.: the connective tissue. Red blood-corpuscles are produced from lumps of living matter whenever, in the young, one variety of connective tissue is transformed into another —f. i., cartilage into bone. After the organism has reached full develop- ment, the production of colored blood-corpuscles continues in that variety of connective tissue which longer than any other remains in a juvenile condition, namely, the lymph-tissue. This tissue is present in large quantity in the body—the larger the younger the individual. It exists in all mucous layers, in the medulla of juvenile bone, in the lymph-ganglia, and in the spleen. Unfortunately, in consequence of former misapprehension of the nature and significance of this tissue, it bears the misnomer adenoid tissue. That this tissue is a source of red blood- corpuscles during the entire life-time, will be demonstrated in the next article. Experimental and Microscopical Studies on the Origin of the Blood- globules. By a. W. Johnstone, M. D., Danville, Ky.* The objects of this paper are to give the result of a repetition of Onimus's experiments on the origin of the white blood-corpuscles, and to place on record an account of an undeseribed method of development that is constantly * Arcliivesof Medicine, vol. vi.. Auf,'U'<t. 1881.$