No abstract

For the demonstration or intranuclear vesicles, iodine vapor, formalin vapor, and methyl alcohol fixations give equivalent results when followed by staining with the May-Grünwald Giemsa technique. Neutral buffered formalin and May-Grünwald Giemsa staining demonstrate fewer intranuclear vesicles than the first-mentioned combinations. Iodine vapor or formalin vapor fixations followed by Mayer's haematoxylin staining show greater numbers of nuclei with vesicles.Formalin fixes nuclei slowly, which allows nuclear contraction and thus the squeezing-out of vesicles. Haematoxylin stains protein, while May-Grünwald Giemsa technique does not stain proteins but deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). It therefore follows that the demonstration of vesicles in blast cell nuclei depends on the fixatives and staining methods used.

This paper presents a description of the cells of the normal mesenteric lymph node of the rabbit. The work evolved from a study of the developmental history of the plasmacyte in this organ. The imprint method was used in the preparation of the slides. Several cellular stages not previously recorded in the literature are described.

S m , N. and ENGELBERT, V. E. 1969. Erythropoiesis in chicken peripheral blood. Can. J. Zool. 47: 1269-1273. A form of erythropoiesis murring in the peripheral blood of young domestic chickens which differs radically from descriptions in classical hemtology has been demonstrated with sevcwl staining methods and modern methods or microscopy. New erythrocytes arise directly as nuclear buds from young mature erythrocytes. The new ce!L is n clone, as if were, of the mother cell and clasncal mitosis is not involved. Stages of progressive differentiation In clonc cells terminate witti the mature erythrocyte. The frequency of clone cells in peripheral bIood ranges rrom 3.7% to 6.S%, in sharp contrast to the iigure of 0.2% for mitosis that has been reportcd in the literature.

Counts of granulocytes were performed on thymic imprints from normal rabbits 3 days old, 2–3 weeks old, and young adults, and from young adult rabbits mildly and severely parasitized with coccidiosis. Analyses of percentages of eosinophils, heterophils, and basophils indicated no sex differences. Comparisons of relative numbers of granulocytes in normal rabbits showed that young adult rabbits possessed more eosinophils and fewer basophils than the younger groups (no differences in heterophils); 3-day-old rabbits had more eosinophils than the 2-to 3-week animals (no differences in heterophils and basophils). No differences in relative numbers of the various granulocytes were found in the mildly and severely parasitized rabbits, but there was a decrease in eosinophils in the parasitized rabbits when compared with the young normal adult rabbits. Eosinophilic leukocytes were divided into two groups: the mononuclear "tissue" line and the lobated "blood" line of development. In the 3-day-old rabbits about 95% of eosinophils were of the lobed variety but in the older normal rabbits, the two developmental lines were about equal in numbers. When compared with the normal young adult rabbits, parasitized rabbits have increased percentages of "blood" eosinophils as a result of greater numbers of band and polymorphonuclear cells.