Die Kerngröße in der Schilddrüse von Albinoratten wurde variationsstatistisch untersucht and festgestellt, daß 1. von außen eingeführtes thyreotrophes Hormon oder Einwirkungen, die die thyreotrophe Sekretion des Vorderlappens der Hypophyse erhöhen (Kälteeinwirkung, Frühling, Thiouracilverabreichung, Jodmangel), eine Erhöhung des Kernvolumens hervorrufen. 2. eine Verminderung der thyreotrophen Hormonsekretion hervorrufende Einwirkungen (Hypophysektomie, Thyroxinverabreichung, Hypophysenstielläsion) eine Verminderung des Kernvolumens zur Folge haben. 3. Die Kernvariationsstatistische Methode scheint dazu geeignet zu sein, gewisse funktienelle Zustände des Vorderlappen-Schilddrüsen-Systems quantitativ histologisch zu beurteilen.
Mit dem Reduktionsindicator Triphenyltetrazoliumchlorid (TTC) vorgenommene Vitalfärbung (per os) verursacht eine dem morphologisch-funtionellen Zustand des Magens entsprechende Triphenylformazan-(TF-)-Bildung. Die TF-Bildung konnte mit auf sekretions und motorische Funktion des Magens einwirkenden Pharmakonen beeinflußt werden. Die wahrgenommene Erscheinung zeigt sich zum Studium “in vivo” der morphologisch-funktionellen Einheit des Magens geeignet.
This paper deals with a study of the effects of infrared radiation (10, 000 A°) on the Ehrlich ascites tumor. Total body radiation was given continuously for a 24 day period. Mitotic indices were determined daily for treated and control groups throughout the period of radiation. Growth and survival curves were determined from data collected at three day intervals for a period of 45 days. Comparative cytological studies were made. Solid tumors frequently developed in the treated group. Infrared apparently had a stimulatory effect on the tumor employed as reflected by mitotic indices and comparative growth curve studies. Higher percentages of animals survived with infrared treatment as opposed to the controls. Infrared appeared to have a direct physical effect on the cell and its constituents and may act indirectly by interfering with various physiological processes.
1. In our previous phase microscope studies, various interkinetic nuclei were described, in which the chromonema structure is either (a) uncoiled completely, or (b) remained in varied degree after mitosis. The cells belonging to the latter group (b) such as lymphocytes, monocytes and plasma cells in mice, referring especially to their chromonema structure as seen in ultrathin section by an electron microscope, are herewith reported. 2. In the interkinetic nucleus of lymphocytes, monocytes and plasma cells, varying spiral structures were recognized corresponding to the configuration of coiled and uncoiled chromonema. Among the spiral fibers the following varieties according to the modes of the arrangement and their diameterical sizes may be distinguished: Chromosome 500mμ, 440-480mμ Chromonema 100-120mμ in contraction, 60mμ, 30-35mμ in loosening Subchromonema 26-30mμ in contraction, 13mμ in loosening Protochromonema ca. 2-3mμ The diametrical size of these elements fluctuates according to the intensity of the coiling, namely, it is large in high contraction, while small in loosening. 3. The protochromonemata belong to the morphological limit capable of being observed by an electron microscope in ultrathin sections. The size (in diameter) of this fiber is very similar to the fibers of the extracted nucleoprotein recently reported by Kahler and Lloyd (24Å). The fine filament of protochromonema found in monocytes is wristed even in an extremely unravelled state. 4. This observation was confirmed also with a structure of the more or less loosely coiled chromosomes found in mitotic lymphocytes in prophase. 5. The size and structure of the chromonema and subchromonema in mitotic and interkinetic stages were discussed.
The cytogenetic behavior of 66 hybrids between Oenothera affinis and Oenothera mollissima has been described. Races Carrasco, Buenos Aires, and Argentina of O. mollissima have been shown to be “heterogamous” as pollen parent, but “isogamous” as seed parent. Races Toledo, Florida and Palermo of O. affinis proved to be isogamous as either parent. Evidence concerning the behavior of gametic lethals is less certain for the other races of O. mollissima, but they too probably follow the pattern presented above. Evidence has also been presented for the occurrence of various types of zygotic lethals. Hybrids which could be classified as one or the other of the two species have been discussed. The phylogenetic relationships between the various races of O. affinis and O. mollissima have been pointed out. The various races of O. mollissima were found to be more distantly related to one another with respect to segmental interchanges than they were to the races of O. affinis. The cytogenetic evidence, thus, favors a consolidation of O. affinis and O. mollissima under a single species.
1. The cytology of the subtribe Saccharinae, including chromosome numbers and meiotic behavior, is reviewed. 2. Chromosome numbers and behavior are reported for the first time for three genera, Eccoilopus, Spodiopogon, and Eulalia. 3. Twelve genera and twenty-eight species of the subtribe have now been studied cytologically. 4. Polyploidy is shown to occur in all genera in which more than one species has been studied. 5. Several different basic numbers are indicated but five (or ten) is by far the most frequently reported. 6. All chromosomes in the subtribe are small, but some are much smaller than others and there seems to be a phylogenetic trend from the larger to the smaller. 7. Some of the general morphological differences in the subtribe are discussed, especially in relationship to phylogeny. 8. An attempt is made, by combining morphological and cytological data, to diagram a likely path of evolution for the subtribe.